hghave: list the module needed for the `vcr` check
I'm tired of having to look up modules each time I setup a system, and try to
distinguish between similar package names to get the right one. Now that the
search API has been disabled, it's even harder. There are other python packages
here that should be listed like this, but this is the one that came up missing
today, so it's a start.
Differential Revision: https://phab.mercurial-scm.org/D9879
# 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"]