USE="libressl mta pam" emerge =mail-mta/opensmtpd-6.0.2_p1-r1 fails with error: ../../smtpd/smtpd.c: In function ‘parent_shutdown’: ../../smtpd/smtpd.c:329:17: error: ‘WAIT_MYPGRP’ undeclared (first use in this function) pid = waitpid(WAIT_MYPGRP, NULL, 0); Reproducible: Always Steps to Reproduce: 1. USE="libressl mta pam" emerge =mail-mta/opensmtpd-6.0.2_p1-r1 Actual Results: compile fails Expected Results: build successfully Autoconf detects that WAIT_MYPGRP is not available and sets HAVE_DECL_WAIT_MYPGRP to 0: config.log:| #define HAVE_DECL_WAIT_MYPGRP 0 However the source code uses a #ifndef: openbsd-compat/openbsd-compat.h:#ifndef HAVE_DECL_WAIT_MYPGRP As a workaround I changed this line to: openbsd-compat/openbsd-compat.h:#if HAVE_DECL_WAIT_MYPGRP != 1 With this change it builds correctly.