tests/test-empty-dir.t

pyoxidizer: force pip to not use pep517 in order to be able to install hg

Mercurial is not (yet) a pep517 package, but the presence of a pyproject.toml
file tells newer-ish versions of pip that it should be one.

This is related to 58fe6d127a01, and fixes pyoxidizer builds for the Heptapod
CI.

Differential Revision: https://phab.mercurial-scm.org/D11710

  $ hg init

  $ echo 123 > a
  $ hg add a
  $ hg commit -m "first" a

  $ mkdir sub
  $ echo 321 > sub/b
  $ hg add sub/b
  $ hg commit -m "second" sub/b

  $ cat sub/b
  321

  $ hg co 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ cat sub/b 2>/dev/null || echo "sub/b not present"
  sub/b not present

  $ test -d sub || echo "sub not present"
  sub not present