1. I was trying to compile from ports:

make (without any flags)

Got an error:

cc1: error: unrecognized command line option "-Wno-duplicate-decl-specifier"

cc1: error: unrecognized command line option "-Wno-duplicate-decl-specifier"

cc1: error: unrecognized command line option "-Wno-duplicate-decl-specifier"

cc1: error: unrecognized command line option "-Wno-duplicate-decl-specifier"

*** [edit-mail.lo] Error code 1

*** [program-client-local.lo] Error code 1

*** [program-client-remote.lo] Error code 1

*** [rfc2822.lo] Error code 1

4 errors

*** [all-recursive] Error code 1

1 error

*** [all-recursive] Error code 1

1 error

*** [all-recursive] Error code 1

1 error

*** [all] Error code 2

1 error

===> Compilation failed unexpectedly.

Try to set MAKE_JOBS_UNSAFE=yes and rebuild before reporting the failure to the maintainer.

*** [do-build] Error code 1

Stop in /usr/ports/mail/dovecot2-pigeonhole.

*** [stage] Error code 1

2. When, I was trying to add flag -k (force). Same error.

3. When, I was trying to add flag MAKE_JOBS_UNSAFE. Same error.