See https://bugs.llvm.org/show_bug.cgi?id=43830, but basically the follwing code:

```
// a.c
#include <Python.h>

int main() {
  Py_Initialize();
  PyRun_SimpleString("import readline; print(readline.__doc__)");
  return 0;
}
```

compiled like this:

```
% gcc a.c `./install/bin/python3-config --cflags --ldflags --libs` -lpython3.9
```

runs fine:

```
% ./a.out                                          
Importing this module enables command line editing using GNU readline.
```

However the following:

```
% gcc a.c `./install/bin/python3-config --cflags --ldflags --libs` -ledit -lpython3.9
```

compiles but segfaults at runtime.

This appears to be essentially a duplicate of Issue13631 which has long proposed full support of libedit.

@ned I(d rather see this as an evolution of Issue13631, as this solves a problem when libreadline and libedit are both loaded in the same executable. As such, using libedit instead of readline wouldn't solve the issue: what if the program Python is embeded in is linked to readline?

I find python approach relatively elegant: detect the linked library at runtime and use the ad-hoc implementation based on this.

An other option would be to dlopen readline using the RTLD_LOCAL flag, so that we get a better, non intrusive symbol resolution.

What do you think?

New changeset 7105319ada2e663659020cbe9fdf7ff38f421ab2 by Victor Stinner (serge-sans-paille) in branch 'master':
 bpo-38634: Allow non-apple build to cope with libedit (GH-16986)
https://github.com/python/cpython/commit/7105319ada2e663659020cbe9fdf7ff38f421ab2

New changeset 68669ef7883ea6338ca441e50f4f9d975f54d017 by Miss Islington (bot) in branch '3.8':
bpo-38634: Allow non-apple build to cope with libedit (GH-16986)
https://github.com/python/cpython/commit/68669ef7883ea6338ca441e50f4f9d975f54d017

Thanks serge-sans-paille for the bug report and the fix!

I backported it to 3.8 since it could be automated, but I don't think that it's worth it to backport it to 3.7:
https://github.com/python/cpython/pull/16986#issuecomment-561711232