We don't want to be holding references to temporary directories
longer than necessary, an Gcf is intended to be long-lived.
# {topdir} means ExtSearch (likely [extindex "all"]) with potentially
# 100K alternates. git(1) has a proposed patch for 100K alternates:
# <https://lore.kernel.org/git/20210624005806.12079-1-e@80x24.org/>
- if (!defined($ibx->{topdir}) && ($GCF2C //= eval {
+ if (!defined($ibx->{topdir}) && !defined($git->{-tmp}) &&
+ ($GCF2C //= eval {
require PublicInbox::Gcf2Client;
PublicInbox::Gcf2Client::new();
} // 0)) { # 0: do not retry if libgit2 or Inline::C are missing