diff --git a/tests/test-copies-chain-merge.t b/tests/test-copies-chain-merge.t
--- a/tests/test-copies-chain-merge.t
+++ b/tests/test-copies-chain-merge.t
@@ -25,7 +25,6 @@
   >         l = "%s       *%s" % (line[:6], line[14:].rstrip())
   >         print(l)
   > EOF
-  $ chmod +x no-linkrev
 
   $ cat << EOF >> $HGRCPATH
   > [diff]
@@ -481,7 +480,7 @@
   created new head
   $ hg mv --force i d
   $ hg commit -m "f-2: rename i -> d"
-  $ hg debugindex d | ../no-linkrev
+  $ hg debugindex d | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * d8252ab2e760 000000000000 000000000000 (no-changeset !)
        0       * ae258f702dfe 000000000000 000000000000 (changeset !)
@@ -537,7 +536,7 @@
   created new head
   $ hg mv --force x t
   $ hg commit -m "r-2: rename t -> x"
-  $ hg debugindex t | ../no-linkrev
+  $ hg debugindex t | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * d74efbf65309 000000000000 000000000000 (no-changeset !)
        1       * 02a930b9d7ad 000000000000 000000000000 (no-changeset !)
@@ -904,7 +903,7 @@
   $ hg up 'desc("f-2")'
   2 files updated, 0 files merged, 2 files removed, 0 files unresolved
 #if no-changeset
-  $ hg debugindex d | ../no-linkrev
+  $ hg debugindex d | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * d8252ab2e760 000000000000 000000000000
        1       * b004912a8510 000000000000 000000000000
@@ -915,7 +914,7 @@
        6       * 89c873a01d97 7b79e2fe0c89 17ec97e60577
        7       * d55cb4e9ef57 000000000000 000000000000
 #else
-  $ hg debugindex d | ../no-linkrev
+  $ hg debugindex d | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * ae258f702dfe 000000000000 000000000000
        1       * b004912a8510 000000000000 000000000000
@@ -949,7 +948,7 @@
   1c334238bd42ec85c6a0d83fd1b2a898a6a3215d 644   d (no-changeset !)
   cea2d99c0fde64672ef61953786fdff34f16e230 644   d (changeset !)
 #if no-changeset
-  $ hg debugindex d | ../no-linkrev
+  $ hg debugindex d | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * d8252ab2e760 000000000000 000000000000
        1       * b004912a8510 000000000000 000000000000
@@ -961,7 +960,7 @@
        7       * d55cb4e9ef57 000000000000 000000000000
        8       * 1c334238bd42 7b79e2fe0c89 000000000000
 #else
-  $ hg debugindex d | ../no-linkrev
+  $ hg debugindex d | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * ae258f702dfe 000000000000 000000000000
        1       * b004912a8510 000000000000 000000000000
@@ -2327,7 +2326,7 @@
   $ hg manifest --debug --rev 'desc("b-1")' | grep '644   d'
   d8252ab2e760b0d4e5288fd44cbd15a0fa567e16 644   d (no-changeset !)
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   d (changeset !)
-  $ hg debugindex d | head -n 4 | ../no-linkrev
+  $ hg debugindex d | head -n 4 | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * d8252ab2e760 000000000000 000000000000 (no-changeset !)
        0       * ae258f702dfe 000000000000 000000000000 (changeset !)
@@ -2400,7 +2399,7 @@
   b76eb76580df486c3d51d63c5c210d4dd43a8ac7 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   e8825b386367b29fec957283a80bb47b47483fe1 644   f
-  $ hg debugindex f | ../no-linkrev
+  $ hg debugindex f | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * b76eb76580df 000000000000 000000000000
        1       * e8825b386367 000000000000 000000000000
@@ -2416,7 +2415,7 @@
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   f
-  $ hg debugindex f | ../no-linkrev
+  $ hg debugindex f | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * ae258f702dfe 000000000000 000000000000
        1       * d3613c1ec831 ae258f702dfe 000000000000
@@ -2988,7 +2987,7 @@
   3f91841cd75cadc9a1f1b4e7c1aa6d411f76032e 644   v
   $ hg manifest --debug --rev 'desc("q-2")' | grep '644   v'
   c43c088b811fd27983c0a9aadf44f3343cd4cd7e 644   v
-  $ hg debugindex v | ../no-linkrev
+  $ hg debugindex v | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * 3f91841cd75c 000000000000 000000000000
        1       * c43c088b811f 000000000000 000000000000
@@ -3003,7 +3002,7 @@
   5aed6a8dbff0301328c08360d24354d3d064cf0d 644   v
   $ hg manifest --debug --rev 'desc("q-2")' | grep '644   v'
   a38b2fa170219750dac9bc7d19df831f213ba708 644   v
-  $ hg debugindex v | ../no-linkrev
+  $ hg debugindex v | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * 5aed6a8dbff0 000000000000 000000000000
        1       * a38b2fa17021 000000000000 000000000000
@@ -3286,7 +3285,7 @@
   b76eb76580df486c3d51d63c5c210d4dd43a8ac7 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   e8825b386367b29fec957283a80bb47b47483fe1 644   f
-  $ hg debugindex f | ../no-linkrev
+  $ hg debugindex f | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * b76eb76580df 000000000000 000000000000
        1       * e8825b386367 000000000000 000000000000
@@ -3302,7 +3301,7 @@
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   ae258f702dfeca05bf9b6a22a97a4b5645570f11 644   f
-  $ hg debugindex f | ../no-linkrev
+  $ hg debugindex f | "$PYTHON" ../no-linkrev
      rev linkrev nodeid       p1           p2
        0       * ae258f702dfe 000000000000 000000000000
        1       * d3613c1ec831 ae258f702dfe 000000000000