Current master-2.2 branch of Dovecot compiles for me on Gentoo x86_64 but experiences symbol errors when starting up:
Jun 24 08:38:00 thunderstorm dovecot: lmtp(8180): Fatal: Couldn't load required plugin /usr/lib64/dovecot/libssl_iostream_openssl.so: dlopen() failed: /usr/lib64/dovecot/libssl_iostream_openssl.so: undefined symbol: SSL_COMP_free_compression_methods Jun 24 08:38:00 thunderstorm dovecot: master: Error: service(lmtp): command startup failed, throttling for 16 secs
I suspect that this is because I have libressl installed on my systems instead of OpenSSL.
A known commit point which does not work is:
f5e6b05684328b9800ccd973c73027300c832d65
However a few commits earlier this problem does not occur:
f292589f4b85e02d97d974dfe34324c6c0bb9d9f
Looks like commit bff052bd29dbf7175ee6cd14bd14bcea1900b869 : "lib-dcrypt, lib-ssl-iostream: Share OpenSSL init/deinit code." may have broken the tree for LibreSSL/non OpenSSL users.
Reuben