We accidentally ran the dovecot 2.3.14 testsuite on a host where clock_gettime (and probably time and gettimeofday) succeed, but set errno to ENOSYS. This behavior is unusual, but permitted by POSIX: successful function calls can overwrite errno, as long as they don't set it to 0.

The relevant log excerpt looks like this:

make[3]: Entering directory '/builddir/build/BUILD/dovecot-2.3.14/src/master'
for bin in test-auth-client test-auth-master test-master-login-auth; do \
if ! ./$bin; then exit 1; fi;
done test-common.c:200: Assert failed: suppress == TRUE
connection refused: run (ret == -1) .................................. : ok: Connection failed CLIENT: Error: auth-client: conn unix:./auth-client-test: connect(./auth-client-test) failed: Function not implemented connection refused ................................................... : FAILED connection timed out: run (ret == -1) ................................ : ok: Connection failed connection timed out: timeout ........................................ : ok connection timed out ................................................. : ok bad version: run (ret == -1) ......................................... : ok: Connection failed bad version .......................................................... : ok disconnect version: run (ret == -1) .................................. : ok: Internal failure disconnect version ................................................... : ok auth PLAIN disconnect: run (ret < 0) ................................. : ok auth PLAIN disconnect ................................................ : ok auth PLAIN reconnect: run (ret < 0) .................................. : ok auth PLAIN reconnect ................................................. : ok auth PLAIN failure: run (ret < 0) .................................... : ok auth PLAIN failure ................................................... : ok auth PLAIN success: run (ret == 0) ................................... : ok auth PLAIN success ................................................... : ok auth LOGIN failure 1: run (ret < 0) .................................. : ok auth LOGIN failure 1 ................................................. : ok auth LOGIN failure 2: run (ret < 0) .................................. : ok auth LOGIN failure 2 ................................................. : ok auth LOGIN success: run (ret == 0) ................................... : ok auth LOGIN success ................................................... : ok auth PLAIN parallel failure: run (ret < 0) ........................... : ok auth PLAIN parallel failure .......................................... : ok auth PLAIN parallel success: run (ret == 0) .......................... : ok auth PLAIN parallel success .......................................... : ok auth LOGIN parallel failure 1: run (ret < 0) ......................... : ok auth LOGIN parallel failure 1 ........................................ : ok auth LOGIN parallel failure 2: run (ret < 0) ......................... : ok auth LOGIN parallel failure 2 ........................................ : ok auth LOGIN parallel success: run (ret == 0) .......................... : ok auth LOGIN parallel success .......................................... : ok 1 / 49 tests failed make[3]: Leaving directory '/builddir/build/BUILD/dovecot-2.3.14/src/master'

“Function not implemented” suggests that dovecot somehow used the clock_gettime (or gettimeofday) ENOSYS error instead of the expected ECONNREFUSED error code. Unfortunately, I have not figured out where this exactly happens.

I don't expect that the problematic glibc build escapes to the wild It was a glibc 2.34 development snapshot, and this particular source of ENOSYS errors is gone again. So fixing this is not urgent.

Thanks, Florian