g95: configure error: 'CLOCK_REALTIME' undeclared (first use in this function)

[tmccabe14]

I am trying to install g95 on my Mac that is currently running macOS Sierra version 10.12.5. I have Xcode version 8.2.1 currently installed. Each time I try and install g95, the log file shows that it tries to fetch the file g95-0.93_4.darwin_16.x86_64.tbz from ​https://packages.macports.org/g95; however, that file does not exist at that URL. The following is the final error message that is displayed.

Error: Failed to configure g95: command execution failed
Processing of port g95 failed

[mf2k (Frank Schima)]

In the future, please Cc the port maintainers (port info --maintainers g95), if any.

Actual error is:

:info:configure /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_g95/g95/work/gcc-4.2.4/g95/./gcc/xgcc -B/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_g95/g95/work/gcc-4.2.4/g95/./gcc/ -B/opt/local/lib/g95/x86_64-apple-darwin16/4.2.4/x86_64-apple-darwin16/bin/ -B/opt/local/lib/g95/x86_64-apple-darwin16/4.2.4/x86_64-apple-darwin16/lib/ -isystem /opt/local/lib/g95/x86_64-apple-darwin16/4.2.4/x86_64-apple-darwin16/include -isystem /opt/local/lib/g95/x86_64-apple-darwin16/4.2.4/x86_64-apple-darwin16/sys-include -DHAVE_CONFIG_H -I. -I../../../libgomp -I. -I../../../libgomp/config/posix -I../../../libgomp -Wall -pthread -Werror -Os -std=gnu89 -MT time.lo -MD -MP -MF .deps/time.Tpo -c ../../../libgomp/config/posix/time.c -o time.o
:info:configure cc1: warnings being treated as errors
:info:configure ../../../libgomp/config/posix/time.c: In function 'omp_get_wtime':
:info:configure ../../../libgomp/config/posix/time.c:56: warning: implicit declaration of function 'clock_gettime'
:info:configure ../../../libgomp/config/posix/time.c:56: error: 'CLOCK_REALTIME' undeclared (first use in this function)
:info:configure ../../../libgomp/config/posix/time.c:56: error: (Each undeclared identifier is reported only once
:info:configure ../../../libgomp/config/posix/time.c:56: error: for each function it appears in.)
:info:configure ../../../libgomp/config/posix/time.c: In function 'omp_get_wtick':
:info:configure ../../../libgomp/config/posix/time.c:73: warning: implicit declaration of function 'clock_getres'
:info:configure ../../../libgomp/config/posix/time.c:73: error: 'CLOCK_REALTIME' undeclared (first use in this function)
:info:configure make[4]: *** [time.lo] Error 1

[ryandesign (Ryan Carsten Schmidt)]

Duplicate of #52990 which was fixed.