Thanks @eejd — the git2/sys/alloc.h include for libgit2 1.8+ is correct. The only thing blocking is DCO: the commit's author email doesn't match its Signed-off-by email, so the DCO check fails. Could you re-sign with a matching identity — git commit --amend -s (with the author email equal to your sign-off email), or git rebase --signoff — then force-push? Once DCO is green I'll merge. 🙏

Thanks for the libgit2 compatibility fix. Before review can continue, please add a DCO Signed-off-by trailer to the non-merge commit and remove any generated/session attribution from commit metadata.

Confirming this fix on another environment — thanks for putting it up.

Repro (macOS arm64, Homebrew libgit2 1.9.4): scripts/build.sh --with-ui fails at the final link step with

internal/cbm/cbm.c:347:12: error: unknown type name 'git_allocator'
  347 |     static git_allocator cbm_git_alloc = {

On libgit2 1.9.4, <git2.h> → common.h only mentions git_allocator in a doc comment; the typedef struct { … } git_allocator; itself lives in the plumbing header git2/sys/alloc.h, which <git2.h> doesn't pull in. Adding #include <git2/sys/alloc.h> (exactly this PR) makes it compile and link cleanly, and the resulting binary indexes normally.

So this reproduces beyond 1.8+ (also on 1.9.4), and the fix is correct. It looks merge-ready aside from the DCO Signed-off-by trailer — would be great to see it land, since main currently doesn't build against a Homebrew libgit2 without it.

Thank you for finding and reporting this first — you identified the missing include a full 11 days before anyone else, and that diagnosis is what ultimately got it fixed. We've merged the same fix via #722 (merge efad17d), which was in a mergeable state with a passing DCO check; since the sign-off here never came through and the branch went quiet, we're closing this one as a duplicate rather than leaving it open. The first-finder credit is yours — thanks again for the sharp catch, and we'd be happy to see more contributions from you.