Build of gnupg2 in version 2.4.5 (with npth) fails since https://git.gnupg.org/cgi-bin/gitweb.cgi?p=npth.git;a=commitdiff;h=02ce6b2d27f91ed6285e4e92d99c21bcc7823c9b because
busy_wait_for is only defined if !HAVE_PTHREAD_MUTEX_TIMEDLOCK. However, busy_wait_for is conditionally used if !HAVE_PTHREAD_MUTEX_TIMEDLOCK, but also if:
- !HAVE_PTHREAD_RWLOCK_TIMEDRDLOCK: https://git.gnupg.org/cgi-bin/gitweb.cgi?p=npth.git;a=blob;f=src/npth.c;h=c0ff8da9dae2ed515d9fedfae2f13bccf3f87c50;hb=HEAD#l492
- HAVE_PTHREAD_RWLOCK_TRYRDLOCK: https://git.gnupg.org/cgi-bin/gitweb.cgi?p=npth.git;a=blob;f=src/npth.c;h=c0ff8da9dae2ed515d9fedfae2f13bccf3f87c50;hb=HEAD#l537
I don't know how to properly fix this issue (without reverting the commit).