Preserve timestamps in copy_dir_contents_to_dir

[jheaff1]

This removes the dependency on autotools for projects such as "make",
where autotools are only invoked if the timestamp of certain files has
changed.

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[jheaff1]

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[jheaff1]

@googlebot I fixed it

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[jheaff1]

@googlebot I fixed it.

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[UebelAndre]

I think this change looks good but does this actually remove a dependency? Where is autotools otherwise being used? Implicitly by cmake?

[jheaff1]

I think this change looks good but does this actually remove a dependency? Where is autotools otherwise being used? Implicitly by cmake?

It seems that if you have a machine without autotools installed, download make-4.3.2.tar.gz, untar the archive and run:

./configure
./build.sh
sudo ./make install

make will build and install successfully.

If you then copy the extracted folder from make-4.3.tar.gz and run the same commands, then sudo ./make install will fail with the following error:

aclocal-1.16: command not found

along with the warning:

WARNING: 'aclocal-1.16' is missing on your system.
         You should only need it if you modified 'acinclude.m4' or
         'configure.ac' or m4 files included by 'configure.ac'.
         The 'aclocal' program is part of the GNU Automake package:
         <https://www.gnu.org/software/automake>
         It also requires GNU Autoconf, GNU m4 and Perl in order to run:
         <https://www.gnu.org/software/autoconf>
         <https://www.gnu.org/software/m4/>
         <https://www.perl.org/>

The rule in this repo to build make first copies the extracted folder, thereby updating the timestamp of the configure.ac file, invoking the call to aclocal.

By preserving timestamps when copying directories, aclocal is not required to successfully build and install make. This increases hermeticity as there is no reliance on preinstalled autotools

[UebelAndre]

Thanks for the PR and the explanation! 🙏

[jheaff1]

Thanks for the PR and the explanation!

My pleasure! Thank you for maintaining an awesome repo