Since 03eaa48 added perl.withPackages, there is a canonical way to
create a perl interpreter from a list of libraries, for use in script
shebangs or generic build inputs. This method is declarative (what we
are doing is clear), produces short shebangs[1] and needs not to wrap
existing scripts.
Unfortunately there are a few exceptions that I've found:
1. Scripts that are calling perl with the -T switch. This makes perl
ignore PERL5LIB, which is what perl.withPackages is using to inform
the interpreter of the library paths.
2. Perl packages that depends on libraries in their own path. This
is not possible because perl.withPackages works at build time. The
workaround is to add `-I $out/${perl.libPrefix}` to the shebang.
In all other cases I propose to switch to perl.withPackages.
[1]: https://lwn.net/Articles/779997/
continuation of #109595
pkgconfig was aliased in 2018, however, it remained in
all-packages.nix due to its wide usage. This cleans
up the remaining references to pkgs.pkgsconfig and
moves the entry to aliases.nix.
python3Packages.pkgconfig remained unchanged because
it's the canonical name of the upstream package
on pypi.
* writers.makeScriptWriter: fix on Darwin\MacOS
On Darwin a script cannot be used as an interpreter in a shebang line, which
causes scripts produced with makeScriptWriter (and its derivatives) to fail at
run time if the used interpreter was wrapped with makeWrapper (as in the case
of python3.withPackages).
This commit fixes the problem by detecting if the interpreter is a script
and prepending its shebang to the final interpreter line.
For example if used interpreter is;
```
/nix/store/ynwv137n2650qy39swcflxbcygk5jwv1-python3-3.8.3-env/bin/python
```
which is a script with following shebang:
```
#! /nix/store/knd85yc7iwli8344ghav3zli8d9gril0-bash-4.4-p23/bin/bash -e
```
then the shebang line in the produced script will be
```
#! /nix/store/knd85yc7iwli8344ghav3zli8d9gril0-bash-4.4-p23/bin/bash -e /nix/store/ynwv137n2650qy39swcflxbcygk5jwv1-python3-3.8.3-env/bin/python
```
This works on Darwin since there does not seem to be a limit to the length
of the shabang line and the shebang lines support multiple arguments to
the interpreters (as opposed to linux where the kernel imposes a strict limit
on shebang lengh and everything following the interpreter is passed to it
as a single string).
fixes; #93609
related to: #65351#11133 (and probably a bunch of others)
NOTE: scripts produced on platforms other than Darwin will remain unmodified
by this PR. However it might worth considering extending this fix to BSD systems
in general. I didn't do it since I have no way of testing it on systems other
than MacOS and linux.
* writers.makeScriptWriter: fix typo in comment
* writers.makeScriptWriter: fail build if interpreter of interpreter is a script
If we just want to write a non-compiled script (e.g. writeDash), it’s
usually a lot faster just doing it locally. That’s what
`runCommandLocal` was introduced for, so let’s use it in `writers`.
This reduces the size of Hello World [1] from 3.06 MiB to 678 KiB.
[1] As measured by nix-shell -p 'writers.writeHaskellBin "hello" {} "main = putStrLn \"hello\""' --run 'ls -l `which hello`'
