[bug#29856] [PATCH core-updates] guix: python-build-system:, Modify ".py" files in-place.

[Hartmut Goebel]

Hi,

I'm afraid, this patch will lead to quite some serious problems:

• It "kills" the doc-string, which must be the very first _expression_-statement in the program. This might be rarely used, but
  
• it kills "from __future__ import", which must be the first import statement (or even the first statement after any doc-string) to work.

Fixing these issues would require to implement a language-aware scanner, as discussed in <https://lists.gnu.org/archive/html/guix-devel/2017-11/msg00022.html>.

Thus I suggest aiming to implement the solution discussed in that thread (see esp. <https://lists.gnu.org/archive/html/guix-devel/2017-11/msg00041.html>.

Beside of this, the patch suffers from some more issues. Sorry to say :-(

• When converting PYTHONPATH into a list of python strings, these need to be quoted properly.
• The description (commit-message) of the patch is much to terse. It should describe the the reason and implications. Esp. it should describe the case this is fixing.

BTW: The first analysis in <https://bugs.gnu.org/29824> was misleading. I commented there.

-- 
Regards
Hartmut Goebel

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