contrib/plan9/mkfile

tests: restore 'python' and '$TESTDIR/' for dummyssh invocation

This is a backout of 46727fea7a00, and a partial backout of c3ecbf694904.

Windows won't execute 'dummyssh' directly, presumably because CreateProcess()
doesn't know how to execute a bash script:

   $ hg clone -e "dummyssh" ssh://user@dummy/cloned sshclone
   remote: 'dummyssh' is not recognized as an internal or external command,
   remote: operable program or batch file.
   abort: no suitable response from remote hg!
   [255]

With the restoration of python as the executable, $TESTDIR needs to be restored
for these invocations, because python won't search $PATH for 'dummyssh':

   $ hg clone -e "python dummyssh" ssh://user@dummy/cloned sshclone
   remote: python: can't open file 'dummyssh': [Errno 2] No such file or directory
   abort: no suitable response from remote hg!
   [255]

APE=/sys/src/ape
<$APE/config

PYTHON=python
PYTHONBIN=/rc/bin
SH=ape/psh

PURE=--pure
ROOT=../..

# This is slightly underhanded; Plan 9 does not support GNU gettext nor
# does it support dynamically loaded extension modules. We work around
# this by calling build_py and build_scripts directly; this avoids
# additional platform hacks in setup.py.
build:VQ:
	@{
		cd $ROOT
		$SH -c '$PYTHON setup.py $PURE build_py build_scripts'
	}

clean:VQ:
	@{
		cd $ROOT
		$SH -c '$PYTHON setup.py $PURE clean --all'
	}

install:VQ:	build
	@{
		cd $ROOT
		$SH -c '$PYTHON setup.py $PURE install \
			--install-scripts $PYTHONBIN \
			--skip-build \
			--force'
	}
	mkdir -p /lib/mercurial/hgrc.d
	dircp hgrc.d /lib/mercurial/hgrc.d/
	cp 9diff /rc/bin/