32-bit build failure

[AdrianBunk]

https://buildd.debian.org/status/fetch.php?pkg=cppad&arch=armhf&ver=2025.00.00.0-1&stamp=1736795682&raw=0

In file included from /build/reproducible-path/cppad-2025.00.00.0/include/cppad/core/ad.hpp:17,
                 from /build/reproducible-path/cppad-2025.00.00.0/include/cppad/cppad.hpp:45,
                 from /build/reproducible-path/cppad-2025.00.00.0/test_more/debug_rel/debug.cpp:5:
/build/reproducible-path/cppad-2025.00.00.0/include/cppad/local/play/player.hpp:700:9: error: ‘void CppAD::local::player<Base>::setup_random(size_t&)’ cannot be overloaded with ‘void CppAD::local::player<Base>::setup_random(unsigned int&)’
  700 |    void setup_random(size_t& not_used)
      |         ^~~~~~~~~~~~
/build/reproducible-path/cppad-2025.00.00.0/include/cppad/local/play/player.hpp:690:9: note: previous declaration ‘void CppAD::local::player<Base>::setup_random(unsigned int&)’
  690 |    void setup_random(unsigned int& not_used)
      |         ^~~~~~~~~~~~

size_t is unsigned int on 32-bit architectures.

@bradbell I suspect this is caused by commit e52559d.

[bradbell]

It appears that github actions no longer support 32-bit machines; see
https://dev.to/drhyde/automatic-cross-platform-testing-part-6-32-bit-linux-fh2#comment-25ihc

Do you know of a way to get the cppad gitub actions to test a 32 bit machine ?

[bradbell]

I tried to create a container for this case using to docker library i686/ubuntu; see
https://forums.docker.com/t/support-for-32-bit-images-containers-on-64-bit-hosts/10010

The version of cmake was so old that I installed cmake-3.5 using section B of
https://askubuntu.com/questions/355565/how-do-i-install-the-latest-version-of-cmake-from-the-command-line

But that did not help because the version of g++ is so old that C++11 support it is only experimental:
g++ --version
g++ (Ubuntu 4.8.4-2ubuntu1~14.04.4) 4.8.4
Copyright (C) 2013 Free Software Foundation, Inc.

Do you know of a newer 32-bit docker container I can use for testing ?

[barak]

I'm packaging CppAD for Debian, so I'm also interested in getting this resolved.

@bradbell
One way to get a 32-bit build environment would be to make an account on salsa.debian.org (which is Debian's gitlab instance) and use a repo there, turn on automatic building (CI) for specific architectures. Like i686 or x32 or arm32 or whatever. You should also be able to make a 32-bit chroot on a standard amd64 linux machine. Or even just install cross-compilation tools to make "gcc -m32" work and do it in place without any tricky virtual whatnots, by telling it to use the right compilation tools.

[bradbell]

@barak Thanks for the suggestion. I tried the -m32 approach, but ran into a problem (on my machine); see
https://discussion.fedoraproject.org/t/32-bit-stdlibc-conflicts-with-64bit/123280/11

The same approach inside a ubuntu container worked and gave similar errors to above:

[  1%] Building CXX object speed/src/CMakeFiles/speed_src.dir/link_det_lu.cpp.o
In file included from /work/cppad.git/speed/src/link_det_lu.cpp:6:
/work/cppad.git/include/cppad/utility/vector.hpp:182:4: error: 'CppAD::vector<Type>::vector(unsigned int)' cannot be overloaded with 'CppAD::vector<Type>::vector(size_t)'
  182 |    vector(unsigned int n) : capacity_(0), length_(0), data_(nullptr)
      |    ^~~~~~
...

[bradbell]

As it turned out the -m32 flag problem was a problem with my system and has been fixed. This makes it easier to test before future commits.

[bradbell]

@barak I added the -m32 option to the CppAD cmake command; see -m32 on
https://cppad.readthedocs.io/latest/cmake.html#m32
and 01-17 on
https://cppad.readthedocs.io/latest/2025.html#mm-dd-01-17
Thanks

@AdrianBunk I think your bug was fixed by the change to player.hpp in
d00cd6a
Please test the stable/2025 branch on your system.
If it works for you, I plan to make a new release corresponding to the current state of that branch.

[bradbell]

I made the same changes as in stable/2025 using the cppad fedora spec file and the build results went from
https://koji.fedoraproject.org/koji/taskinfo?taskID=127877406
to
https://koji.fedoraproject.org/koji/taskinfo?taskID=128068795

So I am confident that this has fixed the problem and will create the new release.

[bradbell]

The new release is now linked to the documentation for both the stable and latest versions: see Versions on
https://cppad.readthedocs.io/stable-2025/#versions

@AdrianBunk Please close this issue if the new release works for you.

[bradbell]

@barak It appears from the link below that you were having the same problem:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1093006

Feel free to reopen this issue and leave a comment if the following release does not fix it for you
https://github.com/coin-or/CppAD/releases/tag/20250000.1

[barak]

Debian bug 1093006 is indeed fixed by 20250000.1: