[GNC-dev] util/gnc-vcs-info fails if building from a Git worktree (with possible solution)

I have recently discovered that

util/gnc-vcs-info

fails if building from a Git worktree.

Within gnc-vcs-info is this test

# Maybe it's git?
real_gitdir="${real_srcdir}"/.git
if test -d "${real_gitdir}"
then
  ...

however, if you have checked out a Git branch into a worktree,
then .git will be a file containing the string

gitdir: /path/to/main/working/tree/.git/worktrees/branchname

In order to allow gnc-vcs-info to "do the right thing" from
within a Git worktree, I'd suggest adding the following stanza
to gnc-vcs-info, which basically replicates the code from the
existing "Maybe it's git?" block, but allows for the fact that
you know it's a worktree

   fi
 fi

+# Maybe it's a git worktree?
+real_gitdir="${real_srcdir}"/.git
+if test -f "${real_gitdir}"
+then
+  worktrees=`grep worktrees ${real_gitdir}`
+  if test $? = 0 ; then
+
+    if [ "$request" = "type" ]
+    then
+      echo "git"
+      exit 0
+    fi
+
+    # The windows build uses environment variable $GIT_CMD to invoke
git (adding git
+    # to the PATH in Windows results in a build failure).
+    # So for platform independence, use GIT_CMD for all
+    [ -n "$GIT_CMD" ] || GIT_CMD=git
+    if [ "$request" = "date" ]
+    then
+      exec "$GIT_CMD" log -1 --format=%cd --date=short
+      exit 0
+    fi
+
+    githead=`"$GIT_CMD" log -1 --pretty=format:"%h" HEAD 2>/dev/null`
 # short hash only
+    if test $? = 0 ; then
+      /bin/echo -n $githead
+      # Add a "+" to the hash if there deleted or modified files (not
excluded by .gitignore and friends)
+      # "Ignores" untracked files
+      # [ $("$GIT_CMD" ls-files -dkm 2>/dev/null | wc -l) -gt 0 ] &&
/bin/echo -n "+"
+      # Includes untracked files
+      [ $("$GIT_CMD" ls-files -dkmo --exclude-standard 2>/dev/null |
wc -l) -gt 0 ] && /bin/echo -n "+"
+      echo
+      exit 0
+    else
      exit 1
+    fi
+
+  fi
+fi
+
 if test -d "${real_srcdir}"/.bzr ;
 then
   # If we're only interested in the vcs type, then we're done here


or you might want to come up with something else to handle building
from a Git Worktree, in which case feel free to (ab)use the above as
you see fir.

HTH someone who tries to do what I was, when I discovered this
Kevin Buckley