fix: build failure using mingw

[joda01]

Fixed missing include which allows to use getenv

Summary

Changes to recipe: lib/0.8.13

Motivation

Fix build error with mingw under Windows

Details

Added patch which adds #include <stdlib.h>

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• Checked that this PR is not a duplicate: list of PRs by recipe
• Tested locally with at least one configuration using a recent version of Conan

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[joda01]

Relates to #25275

[SpaceIm]

Please consider joda01#1

[uilianries]

@joda01 Thank you for your PR! Please, comment on the issue #4 to be able to run your PR in the CI as well.

[AbrilRBS]

@joda01 please take a look into @SpaceIm PR, it's a better way to implement patches.

I do have a question: Has this issue been reported tp upstream? I'm sure they'd appreciate getting a heads-up!

[joda01]

@AbrilRBS Was this what you meant with better way to provide a patch?
https://github.com/conan-io/conan-center-index/pull/25276/files

When you say 'upstream', do you mean https://directory.fsf.org/wiki/Libelf?

I'm curious if anyone else has encountered similar build issues when using MingW?

[conan-center-bot]

Conan v1 pipeline ✔️

All green in build 6 (5c6229b84ca67189b92d3690a14a70637c37d2f6):

• libelf/0.8.13:
  Built 18 packages out of 22 (All logs)

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Conan v2 pipeline ✔️

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All green in build 6 (5c6229b84ca67189b92d3690a14a70637c37d2f6):

• libelf/0.8.13:
  Built 8 packages out of 10 (All logs)