After updating gawk to version 5.0.0, while building libgpg-error 1.36 under MacPorts on Mojave I see the following issue:
libgpg-error v1.36 has been configured as follows: Revision: 85f427f (34292) Platform: x86_64-apple-darwin18.6.0 ---> Building libgpg-error Executing: cd "/opt/local/var/macports/build/_Users_mariusschamschula_Development_MacPorts_ports_devel_libgpg-error/libgpg-error/work/libgpg-error-1.36" && /usr/bin/make -j4 -w all make: Entering directory `/opt/local/var/macports/build/_Users_mariusschamschula_Development_MacPorts_ports_devel_libgpg-error/libgpg-error/work/libgpg-error-1.36' /Applications/Xcode.app/Contents/Developer/usr/bin/make all-recursive make[1]: Entering directory `/opt/local/var/macports/build/_Users_mariusschamschula_Development_MacPorts_ports_devel_libgpg-error/libgpg-error/work/libgpg-error-1.36' Making all in m4 make[2]: Entering directory `/opt/local/var/macports/build/_Users_mariusschamschula_Development_MacPorts_ports_devel_libgpg-error/libgpg-error/work/libgpg-error-1.36/m4' make[2]: Nothing to be done for `all'. make[2]: Leaving directory `/opt/local/var/macports/build/_Users_mariusschamschula_Development_MacPorts_ports_devel_libgpg-error/libgpg-error/work/libgpg-error-1.36/m4' Making all in src make[2]: Entering directory `/opt/local/var/macports/build/_Users_mariusschamschula_Development_MacPorts_ports_devel_libgpg-error/libgpg-error/work/libgpg-error-1.36/src' gawk -f ./mkerrnos.awk ./errnos.in >code-to-errno.h gawk -f ./mkerrcodes1.awk ./errnos.in >_mkerrcodes.h gawk -f ./mkstrtable.awk -v textidx=2 -v nogettext=1 \ ./err-sources.h.in >err-sources-sym.h gawk -f ./mkstrtable.awk -v textidx=2 -v nogettext=1 \ ./err-codes.h.in >err-codes-sym.h gawk: ./mkerrcodes1.awk:84: warning: regexp escape sequence `\#' is not a known regexp operator gawk: ./mkerrnos.awk:86: warning: regexp escape sequence `\#' is not a known regexp operator /usr/bin/clang -E -I/opt/local/include -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk -P _mkerrcodes.h | grep GPG_ERR_ | \ gawk -f ./mkerrcodes.awk >mkerrcodes.h gawk: ./mkstrtable.awk:113: warning: regexp escape sequence `\#' is not a known regexp operator gawk -f ./mkstrtable.awk -v textidx=2 -v nogettext=1 \ -v prefix=GPG_ERR_ -v namespace=errnos_ \ ./errnos.in >errnos-sym.h gawk: ./mkstrtable.awk:113: warning: regexp escape sequence `\#' is not a known regexp operator /usr/bin/clang -g -O0 -I. -I. -o mkheader ./mkheader.c /usr/bin/clang -DHAVE_CONFIG_H -I. -I.. -I/opt/local/include -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk -pipe -Os -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk -arch x86_64 -Wall -Wpointer-arith -MT gen-posix-lock-obj.o -MD -MP -MF .deps/gen-posix-lock-obj.Tpo -c -o gen-posix-lock-obj.o gen-posix-lock-obj.c gawk: fatal: cannot use gawk builtin `namespace' as variable name make[2]: *** [errnos-sym.h] Error 2 make[2]: *** Waiting for unfinished jobs.... gawk: ./mkerrcodes.awk:88: warning: regexp escape sequence `\#' is not a known regexp operator rm _mkerrcodes.h mv -f .deps/gen-posix-lock-obj.Tpo .deps/gen-posix-lock-obj.Po make[2]: Leaving directory `/opt/local/var/macports/build/_Users_mariusschamschula_Development_MacPorts_ports_devel_libgpg-error/libgpg-error/work/libgpg-error-1.36/src' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/opt/local/var/macports/build/_Users_mariusschamschula_Development_MacPorts_ports_devel_libgpg-error/libgpg-error/work/libgpg-error-1.36' make: *** [all] Error 2 make: Leaving directory `/opt/local/var/macports/build/_Users_mariusschamschula_Development_MacPorts_ports_devel_libgpg-error/libgpg-error/work/libgpg-error-1.36' Command failed: cd "/opt/local/var/macports/build/_Users_mariusschamschula_Development_MacPorts_ports_devel_libgpg-error/libgpg-error/work/libgpg-error-1.36" && /usr/bin/make -j4 -w all Exit code: 2