Closed issue by Anachron on void-packages repository

https://github.com/void-linux/void-packages/issues/12991
Description: Trying to build `libgpg-error` results in:

```
=> libgpg-error-1.35_1: running do_build ...
make  all-recursive
make[1]: Entering directory '/builddir/libgpg-error-1.35'
Making all in m4
make[2]: Entering directory '/builddir/libgpg-error-1.35/m4'
make[2]: Nothing to be done for 'all'.
make[2]: Leaving directory '/builddir/libgpg-error-1.35/m4'
Making all in src
make[2]: Entering directory '/builddir/libgpg-error-1.35/src'
gawk -f ./mkerrnos.awk ./errnos.in >code-to-errno.h
gawk: ./mkerrnos.awk:86: warning: regexp escape sequence `\#' is not a known regexp operator
gawk -f ./mkerrcodes1.awk ./errnos.in >_mkerrcodes.h
gawk: ./mkerrcodes1.awk:84: warning: regexp escape sequence `\#' is not a known
regexp operator
cpp   -P _mkerrcodes.h | grep GPG_ERR_ | \
               gawk -f ./mkerrcodes.awk >mkerrcodes.h
gawk: ./mkerrcodes.awk:88: warning: regexp escape sequence `\#' is not a known regexp operator
rm _mkerrcodes.h
cc -I. -I. -o mkerrcodes ./mkerrcodes.c
./mkerrcodes | gawk -f ./mkerrcodes2.awk >code-from-errno.h
gawk: ./mkerrcodes2.awk:94: warning: regexp escape sequence `\#' is not a known
regexp operator
gawk -f ./mkstrtable.awk -v textidx=2 -v nogettext=1 \
        ./err-sources.h.in >err-sources-sym.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 \
        ./err-codes.h.in >err-codes-sym.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: fatal: cannot use gawk builtin `namespace' as variable name
make[2]: *** [Makefile:1617: errnos-sym.h] Error 2
make[2]: Leaving directory '/builddir/libgpg-error-1.35/src'
make[1]: *** [Makefile:509: all-recursive] Error 1
make[1]: Leaving directory '/builddir/libgpg-error-1.35'
make: *** [Makefile:441: all] Error 2
=> ERROR: libgpg-error-1.35_1: do_build: '${make_cmd} ${makejobs} ${make_build_args} ${make_build_target}' exited with 2
=> ERROR:   in do_build() at common/build-style/gnu-configure.sh:13
```

Package versions:
https://github.com/void-linux/void-packages/blob/96d599c51b5073d457da4f4b02577b0b83a484f0/srcpkgs/libgpg-error/template#L3
https://github.com/void-linux/void-packages/blob/76897371064b27d4c83317cef3aad07c846566f5/srcpkgs/gawk/template#L3

Solution: 
https://dev.gnupg.org/T4459

Direct-Link to the `diff`:
https://files.gnupg.net/file/data/2fd7jm7tmuberspsgacl/PHID-FILE-f4dkbycuaum2zpzmdmno/file