diff --git a/contrib/benchmarks/__init__.py b/contrib/benchmarks/__init__.py
--- a/contrib/benchmarks/__init__.py
+++ b/contrib/benchmarks/__init__.py
@@ -81,7 +81,7 @@
     output = ui.popbuffer()
     match = outputre.search(output)
     if not match:
-        raise ValueError("Invalid output {0}".format(output))
+        raise ValueError("Invalid output {}".format(output))
     return float(match.group(1))
 
 
diff --git a/contrib/check-py3-compat.py b/contrib/check-py3-compat.py
--- a/contrib/check-py3-compat.py
+++ b/contrib/check-py3-compat.py
@@ -32,7 +32,7 @@
     for node in ast.walk(root):
         if isinstance(node, ast.ImportFrom):
             if node.module == '__future__':
-                futures |= set(n.name for n in node.names)
+                futures |= {n.name for n in node.names}
         elif isinstance(node, ast.Print):
             haveprint = True
 
diff --git a/contrib/perf.py b/contrib/perf.py
--- a/contrib/perf.py
+++ b/contrib/perf.py
@@ -2523,7 +2523,7 @@
     }
 
     for diffopt in ('', 'w', 'b', 'B', 'wB'):
-        opts = dict((options[c], b'1') for c in diffopt)
+        opts = {options[c]: b'1' for c in diffopt}
 
         def d():
             ui.pushbuffer()
@@ -3048,7 +3048,7 @@
 
     # Verify engines argument.
     if engines:
-        engines = set(e.strip() for e in engines.split(b','))
+        engines = {e.strip() for e in engines.split(b',')}
         for engine in engines:
             try:
                 util.compressionengines[engine]
diff --git a/hgext/absorb.py b/hgext/absorb.py
--- a/hgext/absorb.py
+++ b/hgext/absorb.py
@@ -407,7 +407,7 @@
             involved = [
                 annotated[i] for i in nearbylinenums if annotated[i][0] != 1
             ]
-        involvedrevs = list(set(r for r, l in involved))
+        involvedrevs = list({r for r, l in involved})
         newfixups = []
         if len(involvedrevs) == 1 and self._iscontinuous(a1, a2 - 1, True):
             # chunk belongs to a single revision
@@ -734,10 +734,10 @@
     @property
     def chunkstats(self):
         """-> {path: chunkstats}. collect chunkstats from filefixupstates"""
-        return dict(
-            (path, state.chunkstats)
+        return {
+            path: state.chunkstats
             for path, state in pycompat.iteritems(self.fixupmap)
-        )
+        }
 
     def commit(self):
         """commit changes. update self.finalnode, self.replacemap"""
diff --git a/hgext/closehead.py b/hgext/closehead.py
--- a/hgext/closehead.py
+++ b/hgext/closehead.py
@@ -76,7 +76,7 @@
     heads = []
     for branch in repo.branchmap():
         heads.extend(repo.branchheads(branch))
-    heads = set(repo[h].rev() for h in heads)
+    heads = {repo[h].rev() for h in heads}
     for rev in revs:
         if rev not in heads:
             raise error.Abort(_(b'revision is not an open head: %d') % rev)
diff --git a/hgext/convert/hg.py b/hgext/convert/hg.py
--- a/hgext/convert/hg.py
+++ b/hgext/convert/hg.py
@@ -677,13 +677,9 @@
             for t in self.repo.tagslist()
             if self.repo.tagtype(t[0]) == b'global'
         ]
-        return dict(
-            [
-                (name, nodemod.hex(node))
-                for name, node in tags
-                if self.keep(node)
-            ]
-        )
+        return {
+            name: nodemod.hex(node) for name, node in tags if self.keep(node)
+        }
 
     def getchangedfiles(self, rev, i):
         ctx = self._changectx(rev)
diff --git a/hgext/convert/subversion.py b/hgext/convert/subversion.py
--- a/hgext/convert/subversion.py
+++ b/hgext/convert/subversion.py
@@ -710,11 +710,11 @@
                 # Here/tags/tag.1 discarded as well as its children.
                 # It happens with tools like cvs2svn. Such tags cannot
                 # be represented in mercurial.
-                addeds = dict(
-                    (p, e.copyfrom_path)
+                addeds = {
+                    p: e.copyfrom_path
                     for p, e in pycompat.iteritems(origpaths)
                     if e.action == b'A' and e.copyfrom_path
-                )
+                }
                 badroots = set()
                 for destroot in addeds:
                     for source, sourcerev, dest in pendings:
diff --git a/hgext/eol.py b/hgext/eol.py
--- a/hgext/eol.py
+++ b/hgext/eol.py
@@ -221,7 +221,7 @@
         self.match = match.match(root, b'', [], include, exclude)
 
     def copytoui(self, ui):
-        newpatterns = set(pattern for pattern, key, m in self.patterns)
+        newpatterns = {pattern for pattern, key, m in self.patterns}
         for section in (b'decode', b'encode'):
             for oldpattern, _filter in ui.configitems(section):
                 if oldpattern not in newpatterns:
diff --git a/hgext/fastannotate/commands.py b/hgext/fastannotate/commands.py
--- a/hgext/fastannotate/commands.py
+++ b/hgext/fastannotate/commands.py
@@ -233,7 +233,7 @@
                         showlines=(showlines and not showdeleted),
                     )
                     if showdeleted:
-                        existinglines = set((l[0], l[1]) for l in result)
+                        existinglines = {(l[0], l[1]) for l in result}
                         result = a.annotatealllines(
                             rev, showpath=showpath, showlines=showlines
                         )
diff --git a/hgext/fsmonitor/__init__.py b/hgext/fsmonitor/__init__.py
--- a/hgext/fsmonitor/__init__.py
+++ b/hgext/fsmonitor/__init__.py
@@ -397,7 +397,7 @@
     # for file paths which require normalization and we encounter a case
     # collision, we store our own foldmap
     if normalize:
-        foldmap = dict((normcase(k), k) for k in results)
+        foldmap = {normcase(k): k for k in results}
 
     switch_slashes = pycompat.ossep == b'\\'
     # The order of the results is, strictly speaking, undefined.
@@ -459,22 +459,16 @@
     if normalize:
         # any notable files that have changed case will already be handled
         # above, so just check membership in the foldmap
-        notefiles = set(
-            (
-                normalize(f, True, True)
-                for f in notefiles
-                if normcase(f) not in foldmap
-            )
-        )
-    visit = set(
-        (
-            f
+        notefiles = {
+            normalize(f, True, True)
             for f in notefiles
-            if (
-                f not in results and matchfn(f) and (f in dmap or not ignore(f))
-            )
-        )
-    )
+            if normcase(f) not in foldmap
+        }
+    visit = {
+        f
+        for f in notefiles
+        if (f not in results and matchfn(f) and (f in dmap or not ignore(f)))
+    }
 
     if not fresh_instance:
         if matchalways:
diff --git a/hgext/histedit.py b/hgext/histedit.py
--- a/hgext/histedit.py
+++ b/hgext/histedit.py
@@ -835,10 +835,10 @@
             return ctx, [(self.node, (parentctxnode,))]
 
         parentctx = repo[parentctxnode]
-        newcommits = set(
+        newcommits = {
             c.node()
             for c in repo.set(b'(%d::. - %d)', parentctx.rev(), parentctx.rev())
-        )
+        }
         if not newcommits:
             repo.ui.warn(
                 _(
@@ -2412,7 +2412,7 @@
     Will abort if there are to many or too few rules, a malformed rule,
     or a rule on a changeset outside of the user-given range.
     """
-    expected = set(c.node() for c in ctxs)
+    expected = {c.node() for c in ctxs}
     seen = set()
     prev = None
 
diff --git a/hgext/largefiles/basestore.py b/hgext/largefiles/basestore.py
--- a/hgext/largefiles/basestore.py
+++ b/hgext/largefiles/basestore.py
@@ -67,7 +67,7 @@
         ui = self.ui
 
         at = 0
-        available = self.exists(set(hash for (_filename, hash) in files))
+        available = self.exists({hash for (_filename, hash) in files})
         with ui.makeprogress(
             _(b'getting largefiles'), unit=_(b'files'), total=len(files)
         ) as progress:
diff --git a/hgext/largefiles/overrides.py b/hgext/largefiles/overrides.py
--- a/hgext/largefiles/overrides.py
+++ b/hgext/largefiles/overrides.py
@@ -1564,11 +1564,11 @@
 def overriderollback(orig, ui, repo, **opts):
     with repo.wlock():
         before = repo.dirstate.parents()
-        orphans = set(
+        orphans = {
             f
             for f in repo.dirstate
             if lfutil.isstandin(f) and repo.dirstate[f] != b'r'
-        )
+        }
         result = orig(ui, repo, **opts)
         after = repo.dirstate.parents()
         if before == after:
diff --git a/hgext/largefiles/remotestore.py b/hgext/largefiles/remotestore.py
--- a/hgext/largefiles/remotestore.py
+++ b/hgext/largefiles/remotestore.py
@@ -48,12 +48,12 @@
         )
 
     def exists(self, hashes):
-        return dict(
-            (h, s == 0)
+        return {
+            h: s == 0
             for (h, s) in pycompat.iteritems(
                 self._stat(hashes)
             )  # dict-from-generator
-        )
+        }
 
     def sendfile(self, filename, hash):
         self.ui.debug(b'remotestore: sendfile(%s, %s)\n' % (filename, hash))
diff --git a/hgext/mq.py b/hgext/mq.py
--- a/hgext/mq.py
+++ b/hgext/mq.py
@@ -1162,7 +1162,7 @@
 
         if unknown:
             if numrevs:
-                rev = dict((entry.name, entry.node) for entry in qfinished)
+                rev = {entry.name: entry.node for entry in qfinished}
                 for p in unknown:
                     msg = _(b'revision %s refers to unknown patches: %s\n')
                     self.ui.warn(msg % (short(rev[p]), p))
@@ -3361,7 +3361,7 @@
         ui.write(b'\n')
 
     q = repo.mq
-    applied = set(p.name for p in q.applied)
+    applied = {p.name for p in q.applied}
     patch = None
     args = list(args)
     if opts.get('list'):
diff --git a/hgext/phabricator.py b/hgext/phabricator.py
--- a/hgext/phabricator.py
+++ b/hgext/phabricator.py
@@ -483,7 +483,7 @@
             ]
 
             # "precursors" as known by Phabricator
-            phprecset = set(getnode(d) for d in diffs)
+            phprecset = {getnode(d) for d in diffs}
 
             # Ignore if precursors (Phabricator and local repo) do not overlap,
             # and force is not set (when commit message says nothing)
@@ -1062,7 +1062,7 @@
     # username not found is not an error of the API. So check if we have missed
     # some names here.
     data = result[b'data']
-    resolved = set(entry[b'fields'][b'username'].lower() for entry in data)
+    resolved = {entry[b'fields'][b'username'].lower() for entry in data}
     unresolved = set(names) - resolved
     if unresolved:
         raise error.Abort(
@@ -1635,7 +1635,7 @@
     "differential.query".
     """
     # Prefetch hg:meta property for all diffs
-    diffids = sorted(set(max(int(v) for v in drev[b'diffs']) for drev in drevs))
+    diffids = sorted({max(int(v) for v in drev[b'diffs']) for drev in drevs})
     diffs = callconduit(ui, b'differential.querydiffs', {b'ids': diffids})
 
     patches = []
@@ -1792,11 +1792,11 @@
     """Phabricator differiential status"""
     revs = repo.revs('sort(_underway(), topo)')
     drevmap = getdrevmap(repo, revs)
-    unknownrevs, drevids, revsbydrevid = [], set([]), {}
+    unknownrevs, drevids, revsbydrevid = [], set(), {}
     for rev, drevid in pycompat.iteritems(drevmap):
         if drevid is not None:
             drevids.add(drevid)
-            revsbydrevid.setdefault(drevid, set([])).add(rev)
+            revsbydrevid.setdefault(drevid, set()).add(rev)
         else:
             unknownrevs.append(rev)
 
diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -1936,7 +1936,7 @@
     # applied patch. But it prevents messing up the working directory when
     # a partially completed rebase is blocked by mq.
     if b'qtip' in repo.tags():
-        mqapplied = set(repo[s.node].rev() for s in repo.mq.applied)
+        mqapplied = {repo[s.node].rev() for s in repo.mq.applied}
         if set(destmap.values()) & mqapplied:
             raise error.Abort(_(b'cannot rebase onto an applied mq patch'))
 
@@ -2121,7 +2121,7 @@
 
 def _filterobsoleterevs(repo, revs):
     """returns a set of the obsolete revisions in revs"""
-    return set(r for r in revs if repo[r].obsolete())
+    return {r for r in revs if repo[r].obsolete()}
 
 
 def _computeobsoletenotrebased(repo, rebaseobsrevs, destmap):
diff --git a/hgext/remotefilelog/__init__.py b/hgext/remotefilelog/__init__.py
--- a/hgext/remotefilelog/__init__.py
+++ b/hgext/remotefilelog/__init__.py
@@ -737,7 +737,7 @@
             # "link" is actually wrong here (it is set to len(changelog))
             # if changelog remains unchanged, skip writing file revisions
             # but still do a sanity check about pending multiple revisions
-            if len(set(x[3] for x in pendingfilecommits)) > 1:
+            if len({x[3] for x in pendingfilecommits}) > 1:
                 raise error.ProgrammingError(
                     b'pending multiple integer revisions are not supported'
                 )
diff --git a/hgext/remotefilelog/basepack.py b/hgext/remotefilelog/basepack.py
--- a/hgext/remotefilelog/basepack.py
+++ b/hgext/remotefilelog/basepack.py
@@ -101,7 +101,7 @@
             self._lastpack = pack
             yield pack
 
-        cachedpacks = set(pack for pack in self._lrucache)
+        cachedpacks = {pack for pack in self._lrucache}
         # Yield for paths not in the cache.
         for pack in self._packs - cachedpacks:
             self._lastpack = pack
@@ -259,7 +259,7 @@
         newpacks = []
         if now > self.lastrefresh + REFRESHRATE:
             self.lastrefresh = now
-            previous = set(p.path for p in self.packs)
+            previous = {p.path for p in self.packs}
             for filepath, __, __ in self._getavailablepackfilessorted():
                 if filepath not in previous:
                     newpack = self.getpack(filepath)
diff --git a/hgext/remotefilelog/contentstore.py b/hgext/remotefilelog/contentstore.py
--- a/hgext/remotefilelog/contentstore.py
+++ b/hgext/remotefilelog/contentstore.py
@@ -300,7 +300,7 @@
 
         rl = self._revlog(name)
         ancestors = {}
-        missing = set((node,))
+        missing = {node}
         for ancrev in rl.ancestors([rl.rev(node)], inclusive=True):
             ancnode = rl.node(ancrev)
             missing.discard(ancnode)
diff --git a/hgext/remotefilelog/datapack.py b/hgext/remotefilelog/datapack.py
--- a/hgext/remotefilelog/datapack.py
+++ b/hgext/remotefilelog/datapack.py
@@ -271,9 +271,9 @@
     def cleanup(self, ledger):
         entries = ledger.sources.get(self, [])
         allkeys = set(self)
-        repackedkeys = set(
+        repackedkeys = {
             (e.filename, e.node) for e in entries if e.datarepacked or e.gced
-        )
+        }
 
         if len(allkeys - repackedkeys) == 0:
             if self.path not in ledger.created:
diff --git a/hgext/remotefilelog/historypack.py b/hgext/remotefilelog/historypack.py
--- a/hgext/remotefilelog/historypack.py
+++ b/hgext/remotefilelog/historypack.py
@@ -132,7 +132,7 @@
             known = set()
         section = self._findsection(name)
         filename, offset, size, nodeindexoffset, nodeindexsize = section
-        pending = set((node,))
+        pending = {node}
         o = 0
         while o < size:
             if not pending:
@@ -291,9 +291,9 @@
     def cleanup(self, ledger):
         entries = ledger.sources.get(self, [])
         allkeys = set(self)
-        repackedkeys = set(
+        repackedkeys = {
             (e.filename, e.node) for e in entries if e.historyrepacked
-        )
+        }
 
         if len(allkeys - repackedkeys) == 0:
             if self.path not in ledger.created:
@@ -452,7 +452,7 @@
             sectionstart = self.packfp.tell()
 
             # Write the file section content
-            entrymap = dict((e[0], e) for e in entries)
+            entrymap = {e[0]: e for e in entries}
 
             def parentfunc(node):
                 x, p1, p2, x, x, x = entrymap[node]
diff --git a/hgext/remotefilelog/remotefilelog.py b/hgext/remotefilelog/remotefilelog.py
--- a/hgext/remotefilelog/remotefilelog.py
+++ b/hgext/remotefilelog/remotefilelog.py
@@ -429,7 +429,7 @@
             return nullid
 
         revmap, parentfunc = self._buildrevgraph(a, b)
-        nodemap = dict(((v, k) for (k, v) in pycompat.iteritems(revmap)))
+        nodemap = {v: k for (k, v) in pycompat.iteritems(revmap)}
 
         ancs = ancestor.ancestors(parentfunc, revmap[a], revmap[b])
         if ancs:
@@ -444,7 +444,7 @@
             return nullid
 
         revmap, parentfunc = self._buildrevgraph(a, b)
-        nodemap = dict(((v, k) for (k, v) in pycompat.iteritems(revmap)))
+        nodemap = {v: k for (k, v) in pycompat.iteritems(revmap)}
 
         ancs = ancestor.commonancestorsheads(parentfunc, revmap[a], revmap[b])
         return map(nodemap.__getitem__, ancs)
diff --git a/hgext/remotefilelog/repack.py b/hgext/remotefilelog/repack.py
--- a/hgext/remotefilelog/repack.py
+++ b/hgext/remotefilelog/repack.py
@@ -321,7 +321,7 @@
 
 def _allpackfileswithsuffix(files, packsuffix, indexsuffix):
     result = []
-    fileset = set(fn for fn, mode, stat in files)
+    fileset = {fn for fn, mode, stat in files}
     for filename, mode, stat in files:
         if not filename.endswith(packsuffix):
             continue
diff --git a/hgext/schemes.py b/hgext/schemes.py
--- a/hgext/schemes.py
+++ b/hgext/schemes.py
@@ -97,7 +97,7 @@
             parts = parts[:-1]
         else:
             tail = b''
-        context = dict((b'%d' % (i + 1), v) for i, v in enumerate(parts))
+        context = {b'%d' % (i + 1): v for i, v in enumerate(parts)}
         return b''.join(self.templater.process(self.url, context)) + tail
 
 
diff --git a/hgext/sparse.py b/hgext/sparse.py
--- a/hgext/sparse.py
+++ b/hgext/sparse.py
@@ -246,7 +246,7 @@
             if changedfiles is not None:
                 # In _rebuild, these files will be deleted from the dirstate
                 # when they are not found to be in allfiles
-                dirstatefilestoremove = set(f for f in self if not matcher(f))
+                dirstatefilestoremove = {f for f in self if not matcher(f)}
                 changedfiles = dirstatefilestoremove.union(changedfiles)
 
         return orig(self, parent, allfiles, changedfiles)
diff --git a/hgext/strip.py b/hgext/strip.py
--- a/hgext/strip.py
+++ b/hgext/strip.py
@@ -228,7 +228,7 @@
             for p in repo.dirstate.parents()
         )
 
-        rootnodes = set(cl.node(r) for r in roots)
+        rootnodes = {cl.node(r) for r in roots}
 
         q = getattr(repo, 'mq', None)
         if q is not None and q.applied:
diff --git a/hgext/transplant.py b/hgext/transplant.py
--- a/hgext/transplant.py
+++ b/hgext/transplant.py
@@ -840,10 +840,10 @@
 
         tf = tp.transplantfilter(repo, source, p1)
         if opts.get(b'prune'):
-            prune = set(
+            prune = {
                 source[r].node()
                 for r in scmutil.revrange(source, opts.get(b'prune'))
-            )
+            }
             matchfn = lambda x: tf(x) and x not in prune
         else:
             matchfn = tf
diff --git a/hgext/uncommit.py b/hgext/uncommit.py
--- a/hgext/uncommit.py
+++ b/hgext/uncommit.py
@@ -65,7 +65,7 @@
     base = ctx.p1()
     # ctx
     initialfiles = set(ctx.files())
-    exclude = set(f for f in initialfiles if match(f))
+    exclude = {f for f in initialfiles if match(f)}
 
     # No files matched commit, so nothing excluded
     if not exclude:
@@ -78,9 +78,9 @@
     files = initialfiles - exclude
     # Filter copies
     copied = copiesmod.pathcopies(base, ctx)
-    copied = dict(
-        (dst, src) for dst, src in pycompat.iteritems(copied) if dst in files
-    )
+    copied = {
+        dst: src for dst, src in pycompat.iteritems(copied) if dst in files
+    }
 
     def filectxfn(repo, memctx, path, contentctx=ctx, redirect=()):
         if path not in contentctx:
diff --git a/i18n/polib.py b/i18n/polib.py
--- a/i18n/polib.py
+++ b/i18n/polib.py
@@ -722,8 +722,8 @@
             object POFile, the reference catalog.
         """
         # Store entries in dict/set for faster access
-        self_entries = dict((entry.msgid, entry) for entry in self)
-        refpot_msgids = set(entry.msgid for entry in refpot)
+        self_entries = {entry.msgid: entry for entry in self}
+        refpot_msgids = {entry.msgid for entry in refpot}
         # Merge entries that are in the refpot
         for entry in refpot:
             e = self_entries.get(entry.msgid)
@@ -1808,9 +1808,9 @@
                 entry = self._build_entry(
                     msgid=msgid_tokens[0],
                     msgid_plural=msgid_tokens[1],
-                    msgstr_plural=dict(
-                        (k, v) for k, v in enumerate(msgstr.split(b('\0')))
-                    ),
+                    msgstr_plural={
+                        k: v for k, v in enumerate(msgstr.split(b('\0')))
+                    },
                 )
             else:
                 entry = self._build_entry(msgid=msgid, msgstr=msgstr)
diff --git a/mercurial/ancestor.py b/mercurial/ancestor.py
--- a/mercurial/ancestor.py
+++ b/mercurial/ancestor.py
@@ -138,7 +138,7 @@
         k = 0
         for i in interesting:
             k |= i
-        return set(n for (i, n) in mapping if k & i)
+        return {n for (i, n) in mapping if k & i}
 
     gca = commonancestorsheads(pfunc, *orignodes)
 
diff --git a/mercurial/branchmap.py b/mercurial/branchmap.py
--- a/mercurial/branchmap.py
+++ b/mercurial/branchmap.py
@@ -446,7 +446,7 @@
         # 1 (branch a) -> 2 (branch b) -> 3 (branch a)
         for branch, newheadrevs in pycompat.iteritems(newbranches):
             bheads = self._entries.setdefault(branch, [])
-            bheadset = set(cl.rev(node) for node in bheads)
+            bheadset = {cl.rev(node) for node in bheads}
 
             # This have been tested True on all internal usage of this function.
             # run it again in case of doubt
@@ -582,7 +582,7 @@
 
     @util.propertycache
     def _namesreverse(self):
-        return dict((b, r) for r, b in enumerate(self._names))
+        return {b: r for r, b in enumerate(self._names)}
 
     def branchinfo(self, rev):
         """Return branch name and close flag for rev, using and updating
diff --git a/mercurial/changegroup.py b/mercurial/changegroup.py
--- a/mercurial/changegroup.py
+++ b/mercurial/changegroup.py
@@ -993,7 +993,7 @@
             ]
 
         manifests.clear()
-        clrevs = set(cl.rev(x) for x in clnodes)
+        clrevs = {cl.rev(x) for x in clnodes}
 
         it = self.generatefiles(
             changedfiles,
@@ -1282,9 +1282,7 @@
                 flinkrev = store.linkrev
                 fnode = store.node
                 revs = ((r, flinkrev(r)) for r in store)
-                return dict(
-                    (fnode(r), cln(lr)) for r, lr in revs if lr in clrevs
-                )
+                return {fnode(r): cln(lr) for r, lr in revs if lr in clrevs}
 
         clrevtolocalrev = {}
 
diff --git a/mercurial/cmdutil.py b/mercurial/cmdutil.py
--- a/mercurial/cmdutil.py
+++ b/mercurial/cmdutil.py
@@ -3125,7 +3125,7 @@
         ms = mergemod.mergestate.read(repo)
         mergeutil.checkunresolved(ms)
 
-        filestoamend = set(f for f in wctx.files() if matcher(f))
+        filestoamend = {f for f in wctx.files() if matcher(f)}
 
         changes = len(filestoamend) > 0
         if changes:
@@ -3917,7 +3917,7 @@
         # Apply changes
         fp = stringio()
         # chunks are serialized per file, but files aren't sorted
-        for f in sorted(set(c.header.filename() for c in chunks if ishunk(c))):
+        for f in sorted({c.header.filename() for c in chunks if ishunk(c)}):
             prntstatusmsg(b'revert', f)
         files = set()
         for c in chunks:
diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -3721,9 +3721,9 @@
         heads = [repo[h] for h in heads]
 
     if branchrevs:
-        branches = set(
+        branches = {
             repo[r].branch() for r in scmutil.revrange(repo, branchrevs)
-        )
+        }
         heads = [h for h in heads if h.branch() in branches]
 
     if opts.get(b'active') and branchrevs:
@@ -3731,7 +3731,7 @@
         heads = [h for h in heads if h.node() in dagheads]
 
     if branchrevs:
-        haveheads = set(h.branch() for h in heads)
+        haveheads = {h.branch() for h in heads}
         if branches - haveheads:
             headless = b', '.join(b for b in branches - haveheads)
             msg = _(b'no open branch heads found on branches %s')
diff --git a/mercurial/debugcommands.py b/mercurial/debugcommands.py
--- a/mercurial/debugcommands.py
+++ b/mercurial/debugcommands.py
@@ -584,7 +584,7 @@
     dots = opts.get('dots')
     if file_:
         rlog = revlog.revlog(vfsmod.vfs(encoding.getcwd(), audit=False), file_)
-        revs = set((int(r) for r in revs))
+        revs = {int(r) for r in revs}
 
         def events():
             for r in rlog:
@@ -1134,7 +1134,7 @@
         (b'analyzed', filesetlang.analyze),
         (b'optimized', filesetlang.optimize),
     ]
-    stagenames = set(n for n, f in stages)
+    stagenames = {n for n, f in stages}
 
     showalways = set()
     if ui.verbose and not opts[b'show_stage']:
@@ -2598,7 +2598,7 @@
             dirstatefiles = set(dirstate)
             manifestonly = manifestfiles - dirstatefiles
             dsonly = dirstatefiles - manifestfiles
-            dsnotadded = set(f for f in dsonly if dirstate[f] != b'a')
+            dsnotadded = {f for f in dsonly if dirstate[f] != b'a'}
             changedfiles = manifestonly | dsnotadded
 
         dirstate.rebuild(ctx.node(), ctx.manifest(), changedfiles)
@@ -3165,7 +3165,7 @@
         raise error.Abort(
             _(b'cannot use --verify-optimized with --no-optimized')
         )
-    stagenames = set(n for n, f in stages)
+    stagenames = {n for n, f in stages}
 
     showalways = set()
     showchanged = set()
diff --git a/mercurial/discovery.py b/mercurial/discovery.py
--- a/mercurial/discovery.py
+++ b/mercurial/discovery.py
@@ -188,7 +188,7 @@
         # ancestors of missing
         og._computecommonmissing()
         cl = repo.changelog
-        missingrevs = set(cl.rev(n) for n in og._missing)
+        missingrevs = {cl.rev(n) for n in og._missing}
         og._common = set(cl.ancestors(missingrevs)) - missingrevs
         commonheads = set(og.commonheads)
         og.missingheads = [h for h in og.missingheads if h not in commonheads]
@@ -264,8 +264,8 @@
     # If there are no obsstore, no post processing are needed.
     if repo.obsstore:
         torev = repo.changelog.rev
-        futureheads = set(torev(h) for h in outgoing.missingheads)
-        futureheads |= set(torev(h) for h in outgoing.commonheads)
+        futureheads = {torev(h) for h in outgoing.missingheads}
+        futureheads |= {torev(h) for h in outgoing.commonheads}
         allfuturecommon = repo.changelog.ancestors(futureheads, inclusive=True)
         for branch, heads in sorted(pycompat.iteritems(headssum)):
             remoteheads, newheads, unsyncedheads, placeholder = heads
diff --git a/mercurial/dispatch.py b/mercurial/dispatch.py
--- a/mercurial/dispatch.py
+++ b/mercurial/dispatch.py
@@ -514,7 +514,7 @@
     '''
     # util.interpolate can't deal with "$@" (with quotes) because it's only
     # built to match prefix + patterns.
-    replacemap = dict((b'$%d' % (i + 1), arg) for i, arg in enumerate(args))
+    replacemap = {b'$%d' % (i + 1): arg for i, arg in enumerate(args)}
     replacemap[b'$0'] = name
     replacemap[b'$$'] = b'$'
     replacemap[b'$@'] = b' '.join(args)
diff --git a/mercurial/encoding.py b/mercurial/encoding.py
--- a/mercurial/encoding.py
+++ b/mercurial/encoding.py
@@ -86,10 +86,10 @@
 else:
     # preferred encoding isn't known yet; use utf-8 to avoid unicode error
     # and recreate it once encoding is settled
-    environ = dict(
-        (k.encode('utf-8'), v.encode('utf-8'))
+    environ = {
+        k.encode('utf-8'): v.encode('utf-8')
         for k, v in os.environ.items()  # re-exports
-    )
+    }
 
 _encodingrewrites = {
     b'646': b'ascii',
@@ -285,10 +285,10 @@
 if not _nativeenviron:
     # now encoding and helper functions are available, recreate the environ
     # dict to be exported to other modules
-    environ = dict(
-        (tolocal(k.encode('utf-8')), tolocal(v.encode('utf-8')))
+    environ = {
+        tolocal(k.encode('utf-8')): tolocal(v.encode('utf-8'))
         for k, v in os.environ.items()  # re-exports
-    )
+    }
 
 if pycompat.ispy3:
     # os.getcwd() on Python 3 returns string, but it has os.getcwdb() which
diff --git a/mercurial/exchange.py b/mercurial/exchange.py
--- a/mercurial/exchange.py
+++ b/mercurial/exchange.py
@@ -1679,12 +1679,12 @@
     def headsofdiff(h1, h2):
         """Returns heads(h1 % h2)"""
         res = unfi.set(b'heads(%ln %% %ln)', h1, h2)
-        return set(ctx.node() for ctx in res)
+        return {ctx.node() for ctx in res}
 
     def headsofunion(h1, h2):
         """Returns heads((h1 + h2) - null)"""
         res = unfi.set(b'heads((%ln + %ln - null))', h1, h2)
-        return set(ctx.node() for ctx in res)
+        return {ctx.node() for ctx in res}
 
     while True:
         old_heads = unficl.heads()
diff --git a/mercurial/extensions.py b/mercurial/extensions.py
--- a/mercurial/extensions.py
+++ b/mercurial/extensions.py
@@ -787,11 +787,11 @@
     try:
         from hgext import __index__  # pytype: disable=import-error
 
-        return dict(
-            (name, gettext(desc))
+        return {
+            name: gettext(desc)
             for name, desc in pycompat.iteritems(__index__.docs)
             if name not in _order
-        )
+        }
     except (ImportError, AttributeError):
         pass
 
diff --git a/mercurial/fancyopts.py b/mercurial/fancyopts.py
--- a/mercurial/fancyopts.py
+++ b/mercurial/fancyopts.py
@@ -314,7 +314,7 @@
     argmap = {}
     defmap = {}
     negations = {}
-    alllong = set(o[1] for o in options)
+    alllong = {o[1] for o in options}
 
     for option in options:
         if len(option) == 5:
diff --git a/mercurial/graphmod.py b/mercurial/graphmod.py
--- a/mercurial/graphmod.py
+++ b/mercurial/graphmod.py
@@ -58,7 +58,7 @@
         # partition into parents in the rev set and missing parents, then
         # augment the lists with markers, to inform graph drawing code about
         # what kind of edge to draw between nodes.
-        pset = set(p.rev() for p in ctx.parents() if p.rev() in revs)
+        pset = {p.rev() for p in ctx.parents() if p.rev() in revs}
         mpars = [
             p.rev()
             for p in ctx.parents()
@@ -95,9 +95,9 @@
     include = set(nodes)
     for node in nodes:
         ctx = repo[node]
-        parents = set(
+        parents = {
             (PARENT, p.rev()) for p in ctx.parents() if p.node() in include
-        )
+        }
         yield (ctx.rev(), CHANGESET, ctx, sorted(parents))
 
 
diff --git a/mercurial/hbisect.py b/mercurial/hbisect.py
--- a/mercurial/hbisect.py
+++ b/mercurial/hbisect.py
@@ -137,7 +137,7 @@
             side = state[b'bad']
         else:
             side = state[b'good']
-        num = len(set(i.node() for i in parents) & set(side))
+        num = len({i.node() for i in parents} & set(side))
         if num == 1:
             return parents[0].ancestor(parents[1])
     return None
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -1809,7 +1809,7 @@
         # map tag name to (node, hist)
         alltags = tagsmod.findglobaltags(self.ui, self)
         # map tag name to tag type
-        tagtypes = dict((tag, b'global') for tag in alltags)
+        tagtypes = {tag: b'global' for tag in alltags}
 
         tagsmod.readlocaltags(self.ui, self, alltags, tagtypes)
 
@@ -1822,12 +1822,10 @@
             if node != nullid:
                 tags[encoding.tolocal(name)] = node
         tags[b'tip'] = self.changelog.tip()
-        tagtypes = dict(
-            [
-                (encoding.tolocal(name), value)
-                for (name, value) in pycompat.iteritems(tagtypes)
-            ]
-        )
+        tagtypes = {
+            encoding.tolocal(name): value
+            for (name, value) in pycompat.iteritems(tagtypes)
+        }
         return (tags, tagtypes)
 
     def tagtype(self, tagname):
diff --git a/mercurial/match.py b/mercurial/match.py
--- a/mercurial/match.py
+++ b/mercurial/match.py
@@ -772,7 +772,7 @@
         candidates = self._fileset | self._dirs - {b''}
         if dir != b'':
             d = dir + b'/'
-            candidates = set(c[len(d) :] for c in candidates if c.startswith(d))
+            candidates = {c[len(d) :] for c in candidates if c.startswith(d)}
         # self._dirs includes all of the directories, recursively, so if
         # we're attempting to match foo/bar/baz.txt, it'll have '', 'foo',
         # 'foo/bar' in it. Thus we can safely ignore a candidate that has a
diff --git a/mercurial/mdiff.py b/mercurial/mdiff.py
--- a/mercurial/mdiff.py
+++ b/mercurial/mdiff.py
@@ -91,7 +91,7 @@
             )
 
     def copy(self, **kwargs):
-        opts = dict((k, getattr(self, k)) for k in self.defaults)
+        opts = {k: getattr(self, k) for k in self.defaults}
         opts = pycompat.strkwargs(opts)
         opts.update(kwargs)
         return diffopts(**opts)
diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -1796,8 +1796,8 @@
 
 def emptyactions():
     """create an actions dict, to be populated and passed to applyupdates()"""
-    return dict(
-        (m, [])
+    return {
+        m: []
         for m in (
             ACTION_ADD,
             ACTION_ADD_MODIFIED,
@@ -1814,7 +1814,7 @@
             ACTION_PATH_CONFLICT,
             ACTION_PATH_CONFLICT_RESOLVE,
         )
-    )
+    }
 
 
 def applyupdates(
@@ -2070,7 +2070,7 @@
 
     extraactions = ms.actions()
     if extraactions:
-        mfiles = set(a[0] for a in actions[ACTION_MERGE])
+        mfiles = {a[0] for a in actions[ACTION_MERGE]}
         for k, acts in pycompat.iteritems(extraactions):
             actions[k].extend(acts)
             if k == ACTION_GET and wantfiledata:
diff --git a/mercurial/obsolete.py b/mercurial/obsolete.py
--- a/mercurial/obsolete.py
+++ b/mercurial/obsolete.py
@@ -939,7 +939,7 @@
     getnode = repo.changelog.node
     notpublic = _mutablerevs(repo)
     isobs = repo.obsstore.successors.__contains__
-    obs = set(r for r in notpublic if isobs(getnode(r)))
+    obs = {r for r in notpublic if isobs(getnode(r))}
     return obs
 
 
@@ -965,7 +965,7 @@
 def _computesuspendedset(repo):
     """the set of obsolete parents with non obsolete descendants"""
     suspended = repo.changelog.ancestors(getrevs(repo, b'orphan'))
-    return set(r for r in getrevs(repo, b'obsolete') if r in suspended)
+    return {r for r in getrevs(repo, b'obsolete') if r in suspended}
 
 
 @cachefor(b'extinct')
diff --git a/mercurial/obsutil.py b/mercurial/obsutil.py
--- a/mercurial/obsutil.py
+++ b/mercurial/obsutil.py
@@ -194,7 +194,7 @@
 
 def _filterprunes(markers):
     """return a set with no prune markers"""
-    return set(m for m in markers if m[1])
+    return {m for m in markers if m[1]}
 
 
 def exclusivemarkers(repo, nodes):
@@ -338,12 +338,12 @@
         # compute the whole set of successors or descendants
         while len(foreground) != plen:
             plen = len(foreground)
-            succs = set(c.node() for c in foreground)
+            succs = {c.node() for c in foreground}
             mutable = [c.node() for c in foreground if c.mutable()]
             succs.update(allsuccessors(repo.obsstore, mutable))
             known = (n for n in succs if has_node(n))
             foreground = set(repo.set(b'%ln::', known))
-    return set(c.node() for c in foreground)
+    return {c.node() for c in foreground}
 
 
 # effectflag field
@@ -855,11 +855,11 @@
     """ Returns a sorted list of markers users without duplicates
     """
     markersmeta = [dict(m[3]) for m in markers]
-    users = set(
+    users = {
         encoding.tolocal(meta[b'user'])
         for meta in markersmeta
         if meta.get(b'user')
-    )
+    }
 
     return sorted(users)
 
@@ -868,9 +868,9 @@
     """ Returns a sorted list of markers operations without duplicates
     """
     markersmeta = [dict(m[3]) for m in markers]
-    operations = set(
+    operations = {
         meta.get(b'operation') for meta in markersmeta if meta.get(b'operation')
-    )
+    }
 
     return sorted(operations)
 
diff --git a/mercurial/patch.py b/mercurial/patch.py
--- a/mercurial/patch.py
+++ b/mercurial/patch.py
@@ -2888,7 +2888,7 @@
     or 'rename' (the latter two only if opts.git is set).'''
     gone = set()
 
-    copyto = dict([(v, k) for k, v in copy.items()])
+    copyto = {v: k for k, v in copy.items()}
 
     addedset, removedset = set(added), set(removed)
 
diff --git a/mercurial/phases.py b/mercurial/phases.py
--- a/mercurial/phases.py
+++ b/mercurial/phases.py
@@ -445,10 +445,10 @@
                     phasetracking, r, self.phase(repo, r), targetphase
                 )
 
-            roots = set(
+            roots = {
                 ctx.node()
                 for ctx in repo.set(b'roots((%ln::) - %ld)', olds, affected)
-            )
+            }
             if olds != roots:
                 self._updateroots(phase, roots, tr)
                 # some roots may need to be declared for lower phases
@@ -518,9 +518,7 @@
             ]
             updatedroots = repo.set(b'roots(%ln::)', aboveroots)
 
-            finalroots = set(
-                n for n in currentroots if repo[n].rev() < minnewroot
-            )
+            finalroots = {n for n in currentroots if repo[n].rev() < minnewroot}
             finalroots.update(ctx.node() for ctx in updatedroots)
         if finalroots != oldroots:
             self._updateroots(targetphase, finalroots, tr)
@@ -760,7 +758,7 @@
     if not heads or heads == [nullid]:
         return []
     # The logic operated on revisions, convert arguments early for convenience
-    new_heads = set(rev(n) for n in heads if n != nullid)
+    new_heads = {rev(n) for n in heads if n != nullid}
     roots = [rev(n) for n in roots]
     # compute the area we need to remove
     affected_zone = repo.revs(b"(%ld::%ld)", roots, new_heads)
diff --git a/mercurial/pycompat.py b/mercurial/pycompat.py
--- a/mercurial/pycompat.py
+++ b/mercurial/pycompat.py
@@ -334,7 +334,7 @@
         they can be passed as keyword arguments as dictonaries with bytes keys
         can't be passed as keyword arguments to functions on Python 3.
         """
-        dic = dict((k.decode('latin-1'), v) for k, v in dic.items())
+        dic = {k.decode('latin-1'): v for k, v in dic.items()}
         return dic
 
     def byteskwargs(dic):
@@ -342,7 +342,7 @@
         Converts keys of python dictonaries to bytes as they were converted to
         str to pass that dictonary as a keyword argument on Python 3.
         """
-        dic = dict((k.encode('latin-1'), v) for k, v in dic.items())
+        dic = {k.encode('latin-1'): v for k, v in dic.items()}
         return dic
 
     # TODO: handle shlex.shlex().
diff --git a/mercurial/repair.py b/mercurial/repair.py
--- a/mercurial/repair.py
+++ b/mercurial/repair.py
@@ -351,7 +351,7 @@
 def safestriproots(ui, repo, nodes):
     """return list of roots of nodes where descendants are covered by nodes"""
     torev = repo.unfiltered().changelog.rev
-    revs = set(torev(n) for n in nodes)
+    revs = {torev(n) for n in nodes}
     # tostrip = wanted - unsafe = wanted - ancestors(orphaned)
     # orphaned = affected - wanted
     # affected = descendants(roots(wanted))
diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -1286,7 +1286,7 @@
         else:
             start = self.rev(start)
 
-        stoprevs = set(self.rev(n) for n in stop or [])
+        stoprevs = {self.rev(n) for n in stop or []}
 
         revs = dagop.headrevssubset(
             self.revs, self.parentrevs, startrev=start, stoprevs=stoprevs
diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -1875,7 +1875,7 @@
     The set of all parents for all changesets in set, or the working directory.
     """
     if x is None:
-        ps = set(p.rev() for p in repo[x].parents())
+        ps = {p.rev() for p in repo[x].parents()}
     else:
         ps = set()
         cl = repo.changelog
@@ -2437,7 +2437,7 @@
     cl = repo.unfiltered().changelog
     torev = cl.index.get_rev
     tonode = cl.node
-    result = set(torev(n) for n in f(tonode(r) for r in s))
+    result = {torev(n) for n in f(tonode(r) for r in s)}
     result.discard(None)
     return smartset.baseset(result - repo.changelog.filteredrevs)
 
diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -1457,10 +1457,10 @@
     # Merge old parent and old working dir copies
     oldcopies = copiesmod.pathcopies(newctx, oldctx, match)
     oldcopies.update(copies)
-    copies = dict(
-        (dst, oldcopies.get(src, src))
+    copies = {
+        dst: oldcopies.get(src, src)
         for dst, src in pycompat.iteritems(oldcopies)
-    )
+    }
     # Adjust the dirstate copies
     for dst, src in pycompat.iteritems(copies):
         if src not in newctx or dst in newctx or ds[dst] != b'a':
diff --git a/mercurial/store.py b/mercurial/store.py
--- a/mercurial/store.py
+++ b/mercurial/store.py
@@ -137,7 +137,7 @@
     asciistr = list(map(xchr, range(127)))
     capitals = list(range(ord(b"A"), ord(b"Z") + 1))
 
-    cmap = dict((x, x) for x in asciistr)
+    cmap = {x: x for x in asciistr}
     for x in _reserved():
         cmap[xchr(x)] = b"~%02x" % x
     for x in capitals + [ord(e)]:
@@ -200,7 +200,7 @@
     'the~07quick~adshot'
     '''
     xchr = pycompat.bytechr
-    cmap = dict([(xchr(x), xchr(x)) for x in pycompat.xrange(127)])
+    cmap = {xchr(x): xchr(x) for x in pycompat.xrange(127)}
     for x in _reserved():
         cmap[xchr(x)] = b"~%02x" % x
     for x in range(ord(b"A"), ord(b"Z") + 1):
diff --git a/mercurial/upgrade.py b/mercurial/upgrade.py
--- a/mercurial/upgrade.py
+++ b/mercurial/upgrade.py
@@ -1129,7 +1129,7 @@
     """Upgrade a repository in place."""
     if optimize is None:
         optimize = []
-    optimize = set(legacy_opts_map.get(o, o) for o in optimize)
+    optimize = {legacy_opts_map.get(o, o) for o in optimize}
     repo = repo.unfiltered()
 
     revlogs = set(UPGRADE_ALL_REVLOGS)
diff --git a/mercurial/url.py b/mercurial/url.py
--- a/mercurial/url.py
+++ b/mercurial/url.py
@@ -224,13 +224,11 @@
 
 
 def _generic_proxytunnel(self):
-    proxyheaders = dict(
-        [
-            (x, self.headers[x])
-            for x in self.headers
-            if x.lower().startswith('proxy-')
-        ]
-    )
+    proxyheaders = {
+        x: self.headers[x]
+        for x in self.headers
+        if x.lower().startswith('proxy-')
+    }
     self.send(b'CONNECT %s HTTP/1.0\r\n' % self.realhostport)
     for header in pycompat.iteritems(proxyheaders):
         self.send(b'%s: %s\r\n' % header)
diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -2213,7 +2213,7 @@
     '''
 
     def _makefspathcacheentry(dir):
-        return dict((normcase(n), n) for n in os.listdir(dir))
+        return {normcase(n): n for n in os.listdir(dir)}
 
     seps = pycompat.ossep
     if pycompat.osaltsep:
diff --git a/mercurial/utils/storageutil.py b/mercurial/utils/storageutil.py
--- a/mercurial/utils/storageutil.py
+++ b/mercurial/utils/storageutil.py
@@ -364,7 +364,7 @@
     if nodesorder == b'nodes':
         revs = [frev(n) for n in nodes]
     elif nodesorder == b'linear':
-        revs = set(frev(n) for n in nodes)
+        revs = {frev(n) for n in nodes}
         revs = dagop.linearize(revs, store.parentrevs)
     else:  # storage and default
         revs = sorted(frev(n) for n in nodes)
diff --git a/mercurial/windows.py b/mercurial/windows.py
--- a/mercurial/windows.py
+++ b/mercurial/windows.py
@@ -535,13 +535,11 @@
         cache = dircache.get(dir, None)
         if cache is None:
             try:
-                dmap = dict(
-                    [
-                        (normcase(n), s)
-                        for n, k, s in listdir(dir, True)
-                        if getkind(s.st_mode) in _wantedkinds
-                    ]
-                )
+                dmap = {
+                    normcase(n): s
+                    for n, k, s in listdir(dir, True)
+                    if getkind(s.st_mode) in _wantedkinds
+                }
             except OSError as err:
                 # Python >= 2.5 returns ENOENT and adds winerror field
                 # EINVAL is raised if dir is not a directory.
diff --git a/mercurial/wireprototypes.py b/mercurial/wireprototypes.py
--- a/mercurial/wireprototypes.py
+++ b/mercurial/wireprototypes.py
@@ -383,8 +383,8 @@
     # reason for it (like server operators wanting to achieve specific
     # performance characteristics). So fail fast if the config references
     # unusable compression engines.
-    validnames = set(e.name() for e in compengines)
-    invalidnames = set(e for e in configengines if e not in validnames)
+    validnames = {e.name() for e in compengines}
+    invalidnames = {e for e in configengines if e not in validnames}
     if invalidnames:
         raise error.Abort(
             _(b'invalid compression engine defined in %s: %s')
diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -935,11 +935,11 @@
             normalizecrlf('doc/%s.html' % root)
 
         # This logic is duplicated in doc/Makefile.
-        sources = set(
+        sources = {
             f
             for f in os.listdir('mercurial/helptext')
             if re.search(r'[0-9]\.txt$', f)
-        )
+        }
 
         # common.txt is a one-off.
         gentxt('common')
@@ -979,7 +979,7 @@
         # Screen out egg related commands to prevent egg generation.  But allow
         # mercurial.egg-info generation, since that is part of modern
         # packaging.
-        excl = set(['bdist_egg'])
+        excl = {'bdist_egg'}
         return filter(lambda x: x not in excl, install.get_sub_commands(self))
 
 
diff --git a/tests/run-tests.py b/tests/run-tests.py
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -1553,7 +1553,7 @@
     NEEDESCAPE = re.compile(br'[\x00-\x08\x0b-\x1f\x7f-\xff]').search
 
     ESCAPESUB = re.compile(br'[\x00-\x08\x0b-\x1f\\\x7f-\xff]').sub
-    ESCAPEMAP = dict((bchr(i), br'\x%02x' % i) for i in range(256))
+    ESCAPEMAP = {bchr(i): br'\x%02x' % i for i in range(256)}
     ESCAPEMAP.update({b'\\': b'\\\\', b'\r': br'\r'})
 
     def __init__(self, path, *args, **kwds):
@@ -2524,7 +2524,7 @@
 def savetimes(outputdir, result):
     saved = dict(loadtimes(outputdir))
     maxruns = 5
-    skipped = set([str(t[0]) for t in result.skipped])
+    skipped = {str(t[0]) for t in result.skipped}
     for tdata in result.times:
         test, real = tdata[0], tdata[3]
         if test not in skipped:
@@ -2737,7 +2737,7 @@
     @staticmethod
     def _writexunit(result, outf):
         # See http://llg.cubic.org/docs/junit/ for a reference.
-        timesd = dict((t[0], t[3]) for t in result.times)
+        timesd = {t[0]: t[3] for t in result.times}
         doc = minidom.Document()
         s = doc.createElement('testsuite')
         s.setAttribute('errors', "0")  # TODO
@@ -3343,7 +3343,7 @@
         tmpdir = os.path.join(self._hgtmp, b'child%d' % count)
 
         # extra keyword parameters. 'case' is used by .t tests
-        kwds = dict((k, testdesc[k]) for k in ['case'] if k in testdesc)
+        kwds = {k: testdesc[k] for k in ['case'] if k in testdesc}
 
         t = testcls(
             refpath,
diff --git a/tests/simplestorerepo.py b/tests/simplestorerepo.py
--- a/tests/simplestorerepo.py
+++ b/tests/simplestorerepo.py
@@ -588,7 +588,7 @@
             start = nullid
         if stop is None:
             stop = []
-        stoprevs = set([self.rev(n) for n in stop])
+        stoprevs = {self.rev(n) for n in stop}
         startrev = self.rev(start)
         reachable = {startrev}
         heads = {startrev}
diff --git a/tests/test-fastannotate-revmap.py b/tests/test-fastannotate-revmap.py
--- a/tests/test-fastannotate-revmap.py
+++ b/tests/test-fastannotate-revmap.py
@@ -165,7 +165,7 @@
     rm2.flush()
 
     # two files should be the same
-    ensure(len(set(util.readfile(p) for p in [path, path2])) == 1)
+    ensure(len({util.readfile(p) for p in [path, path2]}) == 1)
 
     os.unlink(path)
     os.unlink(path2)
diff --git a/tests/test-hgweb-auth.py b/tests/test-hgweb-auth.py
--- a/tests/test-hgweb-auth.py
+++ b/tests/test-hgweb-auth.py
@@ -52,7 +52,7 @@
         for name in (b'.username', b'.password'):
             if (p + name) not in auth:
                 auth[p + name] = p
-    auth = dict((k, v) for k, v in auth.items() if v is not None)
+    auth = {k: v for k, v in auth.items() if v is not None}
 
     ui = writeauth(auth)
 
diff --git a/tests/test-revlog-raw.py b/tests/test-revlog-raw.py
--- a/tests/test-revlog-raw.py
+++ b/tests/test-revlog-raw.py
@@ -229,7 +229,7 @@
 
     # Gray Code. See https://en.wikipedia.org/wiki/Gray_code
     gray = lambda x: x ^ (x >> 1)
-    reversegray = dict((gray(i), i) for i in range(m))
+    reversegray = {gray(i): i for i in range(m)}
 
     # Generate (n * 2) bit gray code, yield lower n bits as X, and look for
     # the next unused gray code where higher n bits equal to X.
diff --git a/tests/wireprotosimplecache.py b/tests/wireprotosimplecache.py
--- a/tests/wireprotosimplecache.py
+++ b/tests/wireprotosimplecache.py
@@ -116,7 +116,7 @@
             redirectable = False
         else:
             clienttargets = set(self.redirecttargets)
-            ourtargets = set(t[b'name'] for t in loadredirecttargets(self.ui))
+            ourtargets = {t[b'name'] for t in loadredirecttargets(self.ui)}
 
             # We only ever redirect to a single target (for now). So we don't
             # need to store which target matched.