`make artifacts` should not depend on GNU tar and GNU coreutils

[AkihiroSuda]

socket_vmnet/Makefile

Lines 5 to 7 in 8664a96

	# https://reproducible-builds.org/docs/archives/
	TAR ?= gtar --sort=name --mtime="@$(SOURCE_DATE_EPOCH)" --owner=0 --group=0 --numeric-owner --pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime
	TOUCH ?= gtouch -d @$(SOURCE_DATE_EPOCH)

[nirs]

This is not really refactoring, it changes the behaviour. For make artifacts is broken because I don't have gtar.

Replacing gtar with tar does not work:

% make artifacts
rm -rf _artifacts
/Applications/Xcode.app/Contents/Developer/usr/bin/make clean
rm -f socket_vmnet socket_vmnet_client *.o client/*.o
rm -rf _artifacts/x86_64
/Applications/Xcode.app/Contents/Developer/usr/bin/make ARCH=x86_64 DESTDIR=_artifacts/x86_64 install.bin install.doc
cc -O3 -Wall -Wextra -pedantic -DVERSION=\"v1.1.7-49-gd929ac7.m\" -arch x86_64 -c cli.c -o cli.o
cc -O3 -Wall -Wextra -pedantic -DVERSION=\"v1.1.7-49-gd929ac7.m\" -arch x86_64 -c main.c -o main.o
cc -O3 -Wall -Wextra -pedantic -DVERSION=\"v1.1.7-49-gd929ac7.m\" -arch x86_64 -o socket_vmnet  -framework vmnet cli.o main.o
cc -O3 -Wall -Wextra -pedantic -DVERSION=\"v1.1.7-49-gd929ac7.m\" -arch x86_64 -c client/main.c -o client/main.o
cc -O3 -Wall -Wextra -pedantic -DVERSION=\"v1.1.7-49-gd929ac7.m\" -arch x86_64 -o socket_vmnet_client  client/main.o
logger "Installing executables for socket_vmnet v1.1.7-49-gd929ac7.m in _artifacts/x86_64//opt/socket_vmnet/bin"
mkdir -p "_artifacts/x86_64//opt/socket_vmnet/bin"
cp -a socket_vmnet "_artifacts/x86_64//opt/socket_vmnet/bin/socket_vmnet"
cp -a socket_vmnet_client "_artifacts/x86_64//opt/socket_vmnet/bin/socket_vmnet_client"
strip "_artifacts/x86_64//opt/socket_vmnet/bin/socket_vmnet"
strip "_artifacts/x86_64//opt/socket_vmnet/bin/socket_vmnet_client"
logger "Installing documentation for socket_vmnet v1.1.7-49-gd929ac7.m in _artifacts/x86_64//opt/socket_vmnet/share/doc"
mkdir -p "_artifacts/x86_64//opt/socket_vmnet/share/doc/socket_vmnet"
cp -a README.md LICENSE launchd etc_sudoers.d "_artifacts/x86_64//opt/socket_vmnet/share/doc/socket_vmnet"
file -bp _artifacts/x86_64//opt/socket_vmnet/bin/socket_vmnet | grep -q "Mach-O 64-bit executable x86_64"
tar --sort=name --mtime="@1732561936" --owner=0 --group=0 --numeric-owner --pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime -C _artifacts/x86_64 -cf _artifacts/socket_vmnet-1.1.7-49-gd929ac7.m-x86_64.tar ./
tar: Option --sort=name is not supported
Usage:
  List:    tar -tf <archive-filename>
  Extract: tar -xf <archive-filename>
  Create:  tar -cf <archive-filename> [filenames...]
  Help:    tar --help
make: *** [artifacts] Error 1

[nirs]

brew install gnu-tar fixes the issue. If we document it I don't see the issue in using it.

We can add CONTRIBUTING.md with info for developers.

[AkihiroSuda]

This only affects the CI, so not worth documenting

[nirs]

This affects developers that want to try make artifacts locally, added #91