Can't build zsh on 10.13

[kjyv (Stefan Bethge)]

Not sure how this worked in previous osx versions (it did for me), but from ​https://stackoverflow.com/questions/5167269/clock-gettime-alternative-in-mac-os-x it seems that this function is not available. Or should be from 10.12 but the wrong time.h is used.

:info:build make[3]: Entering directory `/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_shells_zsh/zsh/w
ork/zsh-5.4.2/Src/Modules'
:info:build /usr/bin/clang -c -I. -I../../Src -I../../Src -I../../Src/Zle -I. -I/opt/local/include -I/opt/local/include -DHAVE_CONFIG_H -DMODULE -pipe -Os -arch 
x86_64 -fno-common -o datetime..o datetime.c
:info:build datetime.c:188:9: warning: implicit declaration of function 'clock_gettime' is invalid in C99 [-Wimplicit-function-declaration]
:info:build     if (clock_gettime(CLOCK_REALTIME, &now) < 0) {
:info:build         ^
:info:build datetime.c:188:23: error: use of undeclared identifier 'CLOCK_REALTIME'
:info:build     if (clock_gettime(CLOCK_REALTIME, &now) < 0) {
:info:build                       ^
:info:build datetime.c:214:23: error: use of undeclared identifier 'CLOCK_REALTIME'
:info:build     if (clock_gettime(CLOCK_REALTIME, &now) < 0) {
:info:build                       ^
:info:build 1 warning and 2 errors generated.
:info:build make[3]: *** [datetime..o] Error 1

[kurthindenburg (Kurt Hindenburg)]

This is strange - it builds fine here - not sure what the difference would be.

[kjyv (Stefan Bethge)]

Ok, I think it is solved now after - again - updating command line tools from the App store. xcode-select --install said everything was up-to-date.