bug#37615: bug#42534: 28.0.50; package-test-macro-compilation test fails on macOS

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Artur Malabarba <bruce.connor.am@gmail.com>,  37615@debbugs.gnu.org,
>   42534@debbugs.gnu.org
> Date: Fri, 25 Dec 2020 22:43:24 +0100
> 
> The problem on Macos seems to be that it's comparing file-truenames, but
> that's not what's in the load history.  For instance,
> "/var/folders/l4/brbf3lnd693fpdl8bn87q5w80000gn/T/pkg-test-user-dir-FaftUD/macro-problem-1.0/macro-problem-autoloads"
> is in load-history, but it's finding conflicts by truenaming:
> 
> (file-truename 
> "/var/folders/l4/brbf3lnd693fpdl8bn87q5w80000gn/T/pkg-test-user-dir-FaftUD/macro-problem-1.0/macro-problem-autoloads")
> => 
> "/private/var/folders/l4/brbf3lnd693fpdl8bn87q5w80000gn/T/pkg-test-user-dir-FaftUD/macro-problem-1.0/macro-problem-autoloads"
> 
> And indeed:
> 
> larsi@open-catalina test % ls -ld /var
> lrwxr-xr-x@ 1 root  admin  11 Dec 18 15:11 /var -> private/var
> 
> The following seems to fix the problem for me on Macos and doesn't lead
> to any breakages on Debian, so I'm pushing it now.  Can you check
> whether this fixes the problem on Windows?

Yes, thanks.

In my case, the problem was that MS-Windows (in the version I run
here) produces short 8+3 alias file names for long directory names,
the file name for temporary-file-directory didn't compare equal to
what Emacs expected, exactly as on macOS; file-truename fixed that.