setup: copy python3.dll next to hg.exe when building on Windows for hgext.git
I thought I took care of this already, but it must have been that I just
manually copied the file over locally when debugging why the pygit2 library
wasn't loading. The problem with that is what was copied over was from py38,
and then running a py39 build hard crashed when the extension was loaded.
Differential Revision: https://phab.mercurial-scm.org/D10301
# By default Rust will not export dynamic symbols from built executables.
# Python symbols need to be exported from executables in order for that
# executable to load Python extension modules, which are shared libraries.
# Otherwise, the extension module / shared library is unable to resolve
# Python symbols. This file contains target-specific configuration
# overrides to export dynamic symbols from executables.
#
# Ideally we would achieve this functionality via the build.rs build
# script. But custom compiler flags via build scripts apparently only
# support limited options.
[target.x86_64-unknown-linux-gnu]
rustflags = ["-C", "link-args=-Wl,-export-dynamic"]