vsc_tag() always reruns even if the vcs-tag option is disabled. Let's
use custom_target() instead so that we can only enable build_always_stale
if the vcs-tag option is enabled.
[1/9] Generating version.h with a custom command
/home/zbyszek/src/systemd/tools/vcs-tag.sh: line 17: git: command not found
If git is not available, do not try to call it.
When building packages of arbitrary commits of systemd-stable,
distributors might want to include a git sha of the exact commit
they're on. Let's extend vcs-tag a little to make this possible.
If we're on a commit matching a tag, don't generate a git sha at all.
If we're not on a commit matching a tag, generate a vcs tag as usually.
However, if we're not in developer mode, don't append a '^' if the tree
is dirty to accomodate package builds applying various patches to the
tree which shouldn't be considered as "dirty" edits.
q66
Linus Heckemann
Daan De Meyer
Zbigniew Jędrzejewski-Szmek