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.

Ancestors of 5
4 2 0 
Ancestors of 6 and 5
4 3 2 1 0 
Ancestors of 5 and 4
4 2 0 
Ancestors of 7, stop at 6
6 
Ancestors of 7, including revs
7 6 5 4 3 2 1 0 
Ancestors of 7, 5 and 3, including revs
7 6 5 4 3 2 1 0 

Descendants of 5
7 8 
Descendants of 5 and 3
6 7 8 
Descendants of 5 and 4
5 7 8