Build fails on Debian Jessie

[mlocati]

It seems that cmark 0.30.0 can't be compiled on Debian Jessie (compilation of cmark 0.29.0 succeeds):

From within a Docker image launched with docker run --rm -it debian:jessie bash:

$ apt-get update && apt-get install -qy cmake curl g++ python3
[...]
$ cd "$(mktemp -d)"
$ curl -sSL -o - https://github.com/commonmark/cmark/archive/0.30.0.tar.gz | tar xz
$ cd cmark-*
$ make -s -j$(nproc) cmake_build
-- The C compiler identification is GNU 4.9.2
-- The CXX compiler identification is GNU 4.9.2
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Performing Test HAVE_FLAG_ADDRESS_SANITIZER
-- Performing Test HAVE_FLAG_ADDRESS_SANITIZER - Failed
-- Performing Test HAVE_FLAG_SANITIZE_ADDRESS
-- Performing Test HAVE_FLAG_SANITIZE_ADDRESS - Success
-- Performing Test COMPILER_HAS_HIDDEN_VISIBILITY
-- Performing Test COMPILER_HAS_HIDDEN_VISIBILITY - Success
-- Performing Test COMPILER_HAS_HIDDEN_INLINE_VISIBILITY
-- Performing Test COMPILER_HAS_HIDDEN_INLINE_VISIBILITY - Success
-- Performing Test COMPILER_HAS_DEPRECATED_ATTR
-- Performing Test COMPILER_HAS_DEPRECATED_ATTR - Success
-- Looking for stdbool.h
-- Looking for stdbool.h - found
-- Performing Test HAVE___BUILTIN_EXPECT
-- Performing Test HAVE___BUILTIN_EXPECT - Success
-- Performing Test HAVE___ATTRIBUTE__
-- Performing Test HAVE___ATTRIBUTE__ - Success
-- Found PythonInterp: /usr/bin/python3 (found suitable version "3.4.2", minimum required is "3")
-- Configuring done
CMake Error at CMakeLists.txt:42 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:43 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:44 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:50 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:42 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:43 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:44 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:50 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:42 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:43 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:44 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:50 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:42 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:43 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:44 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:50 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:42 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:43 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:44 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


CMake Error at CMakeLists.txt:50 (add_compile_options):
  Error evaluating generator expression:

    $<COMPILE_LANGUAGE:C>

  Expression did not evaluate to a known generator expression


-- Generating done
-- Build files have been written to: /tmp/tmp.KfonX7KiZZ/cmark-0.30.0/build
Makefile:37: recipe for target 'build' failed
make: *** [build] Error 1

[mlocati]

PS:

$ cmake --version
cmake version 3.0.2

[nwellnhof]

COMPILE_LANGUAGE requires CMake 3.3, so cmake_minimum_required should be updated.

[jgm]

OK, let's at least do that. But is it worth thinking about removing this 3.3 only feature instead, to make it more compatible? Does anyone know what the alternative would be?
(This was part of cmake changes submitted by @compnerd -- who might be able to comment on this.)

[jgm]

Btw jessie is oldoldstable, under "extended LTS" support. It wouldn't be crazy to expect people running such an old system to install a more recent cmake, but still, compatibility is good if we can achieve it.

[nwellnhof]

I'm not sure why $<COMPILE_LANGUAGE:C> is needed at all. Shouldn't the language always be C?

[compnerd]

The generator expression for the language is to deal with the Swift build system (that definitely does not do the right thing in many ways). Unfortunately, cleaning that up has been slow going. So, at least for the Swift project, the generator expressions are needed.

[jgm]

Is there a way to work around the issue in cmake without using the newer feature COMPILE_LANGUAGE?

[compnerd]

I think that the way to do that would to not use any add_compile_options at all, and instead explicitly set the options on all the targets via target_compile_options. You could add a function/macro to centralize that if there are too many targets.

[jgm]

If this would work and not add too much complexity, I think it would be desirable to make the project buildable on older systems. However, I don't know much about cmake and wouldn't be able to make these changes myself. Any interest in doing a PR?

It's either this or changing the required cmake_version.

[compnerd]

I think I can take a stab at it and upload a potential change that can restore the build on older versions.