Re: [PATCH] utils: Allow wrap-program to be called multiple times.

[Eric Bavier <ericbavier@gmail.com>]

Ludovic Courtès writes:

> Eric Bavier <ericbavier@gmail.com> skribis:
>
>> Currently, if (@ (guix build utils) wrap-program) is called multiple
>> times for the same file, the original file ends up being overwritten.
>> This happened to me when trying to wrap a python program, which had
>> already once been wrapped by python-build-system.  The
>> python-build-system wrapper sets PYTHON_PATH, and I needed to wrap the
>> program again in order to set PATH.
>
> Wouldn’t it be easier or preferable to change ‘python-build-system’ to
> offer a way to specify additional arguments for ‘wrap-program’?

That was one possibility I considered.

> The idea of having multiple indirections just to set a bunch of
> environment variables doesn’t look appealing to me.

My thought was that it would allow better composability/decoupling of
packages, even if they aren't python packages.  E.g. if a package
inherits from another and needs to wrap an executable, the packager
might not want to bother, or should not need to bother, to check whether
that executable has already been wrapped.

In any case, wrap-program certainly should not silently overwrite an
existing '.foo-real'.

-- 
Eric Bavier

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