tests: use grep -E instead of obsolescent egrep Testing on Fedora 38 failed with: egrep: warning: egrep is obsolescent; using grep -E The warning comes from https://git.savannah.gnu.org/cgit/grep.git/commit/?id=a9515624709865d480e3142fd959bccd1c9372d1 . For further anecdotal evidence of the change, see https://www.phoronix.com/news/GNU-Grep-3.8-Stop-egrep-fgrep . This reverses the code check that goes back to e7d3b509af8b. grep -E is POSIX, but there is a risk that it doesn't work the same on all platforms - especially older Unix versions. It should however always be possible to put a GNU grep in $PATH before running the tests.

--- a/tests/test-subrepo-recursion.t	Mon Jun 26 11:15:30 2023 +0100
+++ b/tests/test-subrepo-recursion.t	Mon Jun 26 14:34:58 2023 +0200
@@ -436,7 +436,7 @@
 
 (unzip date formating is unstable, we do not care about it and glob it out)
 
-  $ unzip -l ../archive.zip | grep -v -- ----- | egrep -v files$
+  $ unzip -l ../archive.zip | grep -v -- ----- | grep -E -v files$
   Archive:  ../archive.zip
     Length [ ]* Date [ ]* Time [ ]* Name (re)
         172  [0-9:\- ]*  .hg_archival.txt (re)