diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -2228,14 +2228,6 @@
         return
     ui.pager(b'config')
     fm = ui.formatter(b'config', opts)
-    for t, f in rcutil.rccomponents():
-        if t == b'path':
-            ui.debug(b'read config from: %s\n' % f)
-        elif t == b'items':
-            for section, name, value, source in f:
-                ui.debug(b'set config by: %s\n' % source)
-        else:
-            raise error.ProgrammingError(b'unknown rctype: %s' % t)
     untrusted = bool(opts.get(b'untrusted'))
 
     selsections = selentries = []
diff --git a/tests/test-config.t b/tests/test-config.t
--- a/tests/test-config.t
+++ b/tests/test-config.t
@@ -266,7 +266,6 @@
   > EOF
 
   $ hg config --debug empty.source
-  read config from: * (glob)
   none: value
   $ hg config empty.source -Tjson
   [
diff --git a/tests/test-hgrc.t b/tests/test-hgrc.t
--- a/tests/test-hgrc.t
+++ b/tests/test-hgrc.t
@@ -170,7 +170,6 @@
 customized hgrc
 
   $ hg showconfig
-  read config from: $TESTTMP/hgrc
   $TESTTMP/hgrc:13: alias.log=log -g
   repo: bundle.mainreporoot=$TESTTMP
   $TESTTMP/hgrc:11: defaults.identify=-n
@@ -187,7 +186,6 @@
 
   $ HGPLAIN=; export HGPLAIN
   $ hg showconfig --config ui.traceback=True --debug
-  read config from: $TESTTMP/hgrc
   repo: bundle.mainreporoot=$TESTTMP
   --config: ui.traceback=True
   --verbose: ui.verbose=False
@@ -197,10 +195,6 @@
 with environment variables
 
   $ PAGER=p1 EDITOR=e1 VISUAL=e2 hg showconfig --debug
-  set config by: $EDITOR
-  set config by: $VISUAL
-  set config by: $PAGER
-  read config from: $TESTTMP/hgrc
   repo: bundle.mainreporoot=$TESTTMP
   $PAGER: pager.pager=p1
   $VISUAL: ui.editor=e2
@@ -223,7 +217,6 @@
   $ HGPLAINEXCEPT=; export HGPLAINEXCEPT
   $ hg showconfig --config ui.traceback=True --debug
   plain: True
-  read config from: $TESTTMP/hgrc
   repo: bundle.mainreporoot=$TESTTMP
   $TESTTMP/hgrc:15: extensions.plain=./plain.py
   --config: ui.traceback=True
@@ -233,7 +226,6 @@
   $ unset HGPLAIN
   $ hg showconfig --config ui.traceback=True --debug
   plain: True
-  read config from: $TESTTMP/hgrc
   repo: bundle.mainreporoot=$TESTTMP
   $TESTTMP/hgrc:15: extensions.plain=./plain.py
   --config: ui.traceback=True
@@ -243,7 +235,6 @@
   $ HGPLAINEXCEPT=i18n; export HGPLAINEXCEPT
   $ hg showconfig --config ui.traceback=True --debug
   plain: True
-  read config from: $TESTTMP/hgrc
   repo: bundle.mainreporoot=$TESTTMP
   $TESTTMP/hgrc:15: extensions.plain=./plain.py
   --config: ui.traceback=True
@@ -259,5 +250,4 @@
   > EOF
   $ hg showconfig --debug paths
   plain: True
-  read config from: $TESTTMP/hgrc
   $TESTTMP/hgrc:17: paths.foo=$TESTTMP/bar