coin-lemon: fixed C++17 and C++20 compilation warnings.

[rturrado]

Specify library name and version: coin-lemon/1.3.1

Fixes issue #15515.

I've recently been playing with a project that is using C++11 and coin-lemon/1.3.1, which is the latest official release of this library. Changing the project's C++ standard to C++23 raises a few compiler warnings, some of them coming from coin-lemon. This commit adds two patches to the coin-lemon recipe that remove the compilation warnings. I have only tried compiling with gcc 12.2.0 on Linux.

---

• I've read the contributing guidelines.
• I've used a recent Conan client version close to the currently deployed.
• I've tried at least one configuration locally with the conan-center hook activated.

[CLAassistant]

All committers have signed the CLA.

[uilianries]

@rturrado Thank you for your patch, could you please send it directly to the upstream? It seems be a portability patch which makes more sense there than here, otherwise, we would need to update it for each new version.

[rturrado]

@uilianries Thanks for the comment! May I ask what do you mean by 'send it directly to the upstream'? Do you mean to send the patch to whoever is maintaining coin-lemon?

I initially thought that's what I should do so, yes. And it should be the library owners who updated the library, gathering the latest patches into a new version, and then created a new conan package with that version.

I tried to create a conan package myself because I saw they hadn't created a new version of the library since 2014 (even though they have been publishing patches until 2021).

Please confirm if I understood you correctly and I will proceed as you suggest.

Thanks again.

[uilianries]

@rturrado Correct, sending to the authors.

I saw they hadn't created a new version of the library since 2014 (even though they have been publishing patches until 2021).

Sorry, I didn't check it. In that case, let's add here, but please, don't forget to send to authors too. I also commented some updates to be added to conandata.yml

Thank you for your contribution!

[rturrado]

I've seen that my changes seem to have broken a compilation with gcc 5.

How can I know all the different combinations a package is built for? And how can I test that locally before uploading?

Thanks, and sorry for the inconveniences I may be causing!

[uilianries]

How can I know all the different combinations a package is built for?

https://github.com/conan-io/conan-center-index/blob/master/docs/supported_platforms_and_configurations.md

And how can I test that locally before uploading?

https://github.com/conan-io/conan-center-index/blob/master/docs/developing_recipes_locally.md#testing-more-environments

Indeed there are many environments, but you don't need to test all them before pushing if you feel safe.

[github-actions]

Hooks produced the following warnings for commit 788b028

coin-lemon/1.3.1

post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libemon.so' links to system library 'm' but it is not in cpp_info.system_libs.

[ghost]

I detected other pull requests that are modifying coin-lemon/all recipe:

• coin-lemon: modernize more for conan v2 #15835

This message is automatically generated by https://github.com/ericLemanissier/conan-center-conflicting-prs so don't hesitate to report issues/improvements there.

[prince-chrismc]

https://github.com/conan-io/conan-center-index/blob/master/docs/adding_packages/sources_and_patches.md#rules

I am not sure the warnings deserve a patch. These are costly to maintain and we really want ones to make "working software"

Does this fail to build with later cppstd? I would prefer less patches otherwise

[rturrado]

Hi @prince-chrismc ,

I'm more in favour of a 'treatiing warnings as errors' policy. Anyway, yes, some of these warnings cause failures when compiling with C++17 or newer (see #15515 ).

Best regards,
Roberto.

[prince-chrismc]

Please add the patch_source too with the PR to upstream were you submitted this 🙏 so others can benefit from it too

[rturrado]

Hi @prince-chrismc ,

I tried to get in touch with the maintainers of the Lemon Graph library via their website and their user mailing list, without luck. The last version of the library is from 2014.

I've issued a new ticket, and attached the first of the patches (C++17), to: https://lemon.cs.elte.hu/trac/lemon/attachment/ticket/680/fix_cpp_17_compilation_warnings.patch
The second patch (C++20) is actually part of this other attachment to a previous ticket (I only took the patch section for array_map.h because the patch section for path.h wasn't patching correctly): http://lemon.cs.elte.hu/trac/lemon/attachment/ticket/631/93c983122692.patch

I think I should update this second patch with the fixes for path.h as well.

If you reckon, I can add those two links mentioned above as patch_source.

Thanks,
Roberto.

[conan-center-bot]

Conan v1 pipeline ❌

Failure in build 6 (a94d7b1fe8cb38927eab847915cc2113710bde1d):

• coin-lemon/1.3.1@:
  CI failed to create some packages (All logs)

  Logs for packageID 42a10e89ce278d2cf0fa1c09abdd40b137b6e79b:

  [settings]
  arch=armv8
  build_type=Debug
  compiler=apple-clang
  compiler.libcxx=libc++
  compiler.version=13.0
  os=Macos
  [options]
  coin-lemon:shared=False
  

  [...]
  Configuration (profile_host):
  [settings]
  arch=armv8
  build_type=Debug
  compiler=apple-clang
  compiler.libcxx=libc++
  compiler.version=13.0
  os=Macos
  [options]
  coin-lemon:shared=False
  [build_requires]
  [env]
  [conf]
  tools.system.package_manager:mode=install
  tools.system.package_manager:sudo=True
  tools.apple:sdk_path=/Applications/conan/xcode/13.0/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.3.sdk
  
  Configuration (profile_build):
  [settings]
  arch=x86_64
  build_type=Debug
  compiler=apple-clang
  compiler.libcxx=libc++
  compiler.version=13.0
  os=Macos
  [options]
  coin-lemon:shared=False
  [build_requires]
  [env]
  [conf]
  tools.system.package_manager:mode=install
  tools.system.package_manager:sudo=True
  tools.apple:sdk_path=/Applications/conan/xcode/13.0/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.3.sdk
  
  coin-lemon/1.3.1: Forced build from source
  Installing package: coin-lemon/1.3.1
  Requirements
      coin-lemon/1.3.1 from local cache - Cache
  Packages
      coin-lemon/1.3.1:42a10e89ce278d2cf0fa1c09abdd40b137b6e79b - Build
  
  Cross-build from 'Macos:x86_64' to 'Macos:armv8'
  Installing (downloading, building) binaries...
  [HOOK - conan-center.py] pre_source(): [IMMUTABLE SOURCES (KB-H010)] OK
  coin-lemon/1.3.1: Configuring sources in /Users/jenkins/w/prod/BuildSingleReference@4/.conan/data/coin-lemon/1.3.1/_/_/source/src
  coin-lemon/1.3.1: Waiting 5 seconds to retry...
  coin-lemon/1.3.1: ERROR: Error downloading file http://lemon.cs.elte.hu/pub/sources/lemon-1.3.1.tar.gz: 'HTTPConnectionPool(host='lemon.cs.elte.hu', port=80): Max retries exceeded with url: /pub/sources/lemon-1.3.1.tar.gz (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x104fe7650>: Failed to establish a new connection: [Errno 8] nodename nor servname provided, or not known'))'
  ERROR: coin-lemon/1.3.1: Error in source() method, line 44
  	destination=self.source_folder, strip_root=True)
  	ConanException: Error downloading file http://lemon.cs.elte.hu/pub/sources/lemon-1.3.1.tar.gz: 'HTTPConnectionPool(host='lemon.cs.elte.hu', port=80): Max retries exceeded with url: /pub/sources/lemon-1.3.1.tar.gz (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x104f968d0>: Failed to establish a new connection: [Errno 8] nodename nor servname provided, or not known'))'
  

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^{Note: To save resources, CI tries to finish as soon as an error is found. For this reason you might find that not all the references have been launched or not all the configurations for a given reference. Also, take into account that we cannot guarantee the order of execution as it depends on CI workload and workers availability.}

---

Conan v2 pipeline (informative, not required for merge) ❌

Note: Conan v2 builds are informative and they are not required for the PR to be merged.

The v2 pipeline failed. Please, review the errors and note this will be required for pull requests to be merged in the near future.

See details:

Failure in build 5 (a94d7b1fe8cb38927eab847915cc2113710bde1d):

• coin-lemon/1.3.1@:
  Error running command conan graph info --requires coin-lemon/1.3.1@#163a480a1ec7e12c4949a9a556f9beec -f json -pr:h /home/conan/w/prod-v2_cci_PR-15516/5/c779839f-b427-402f-badb-3b5bef3bbab8/profile_windows_192_release_dynamic_msvc_release_64.-shared-True.txt -pr:b /home/conan/w/prod-v2_cci_PR-15516/5/c779839f-b427-402f-badb-3b5bef3bbab8/profile_windows_192_release_dynamic_msvc_release_64.-shared-True.txt:

  -------- Input profiles --------
  Profile host:
  [settings]
  arch=x86_64
  build_type=Release
  compiler=msvc
  compiler.runtime=dynamic
  compiler.runtime_type=Release
  compiler.version=192
  os=Windows
  [options]
  */*:shared=True
  
  Profile build:
  [settings]
  arch=x86_64
  build_type=Release
  compiler=msvc
  compiler.runtime=dynamic
  compiler.runtime_type=Release
  compiler.version=192
  os=Windows
  [options]
  */*:shared=True
  
  
  -------- Computing dependency graph --------
  ERROR: coin-lemon/1.3.1: Error in configure() method, line 37
  	del self.options.fPIC
  	ConanException: option 'fPIC' doesn't exist
  Possible options are ['shared']
  

---

^{Note: To save resources, CI tries to finish as soon as an error is found. For this reason you might find that not all the references have been launched or not all the configurations for a given reference. Also, take into account that we cannot guarantee the order of execution as it depends on CI workload and workers availability.}

[stale]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This pull request has been automatically closed because it has not had recent activity. Thank you for your contributions.

[SpaceIm]

@rturrado do you still work on this one? I've hit this issue in coin-lemon while trying to compile OpenMVG with C++20 (#16356 (comment)).

EDIT: I've opened #17338

[rturrado]

Sorry for the late reply, @SpaceIm. I had abandoned this Conan package for a while. I'm glad you're trying to fix it in a new PR.