tests: explicitly define compression engines for tests...
tests: explicitly define compression engines for tests
The zstd compression engine requires C extensions and isn't present
in pure Python builds.
The compression engine list leaks into the server capabilities string.
Unless we're testing functionality specific to a compression format,
the set of compression formats supported by a server doesn't matter
much.
So this commit explicitly defines the server's compression engines for
some tests so behavior is consistent between pure and non-pure builds.
Differential Revision:
https://phab.mercurial-scm.org/D3431
