Since 2.44_01, the behaviour for `check_lib` in their `Makefile.PL` has
been "fixed" to fail when the `assert_lib` function fails to build the
test.
* 2bc1e90c04
Now, this wouldn't be so bad, since it's good to actually test what
stuff is being compiled against.
Except that *something* is wonky with the cross-compilation build-time
Perl.
```
Undefined subroutine &File::Temp::mktemp called at inc/Devel/CheckLib.pm line 236.
```
As far as I know, this is a built-in function from Perl.
* https://perldoc.perl.org/File/Temp.html
Though, something *else* is wrong with `Checklib.pm`. Side-stepping the
issue by (eww) shelling out to `mktemp`, we get these errors:
```
/nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-armv7l-unknown-linux-gnueabihf-binutils-2.31.1/bin/armv7l-unknown-linux-gnueabihf-ld: assertlib_src1_0.553056903257133: file not recognized: file truncated
collect2: error: ld returned 1 exit status
-I/nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-expat-2.2.8-armv7l-unknown-linux-gnueabihf-dev/include -L/nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-expat-2.2.8-armv7l-unknown-linux-gnueabihf/lib -lexpat
/nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-armv7l-unknown-linux-gnueabihf-binutils-2.31.1/bin/armv7l-unknown-linux-gnueabihf-ld: assertlib_src2_0.262169388446154: file not recognized: file truncated
collect2: error: ld returned 1 exit status
Can't link/include C library 'expat.h', 'expat', aborting.
```
Meanwhile, the actual build, while building the library, seemingly has
no issues building using those paths. `¯\_(ツ)_/¯`
Fixes#71296 (Po4a build get stuck in a loop)
Term::ReadKey is an optional dependency. From upstream:
> This module is used to retrieve the terminal's line width.
> If it is not present, the line width can be specified with the COLUMN environment variable.
This reverts commit d0bad145f5.
We don't need this any more, because the generated timestamps are
always set to 1970-01-01.
Reverting this will mean we get man pages for perl programs for free,
because those are generally part of the `install' target.
