utility: add a template alias that will be used in evolve msgs
This template use stack alias s# instead of rev number in messages
printed when we run `hg evolve`.
For example, this template's msgs will look like this:
move:[s3] add aaa
atop:[s2] add bbb
move:[s4] add ccc
I will be using this template in upcoming patches.
#require test-repo
$ checkflake8() {
> if ! (which flake8 > /dev/null); then
> echo skipped: missing tool: flake8;
> exit 80;
> fi;
> };
$ checkflake8
Copied from Mercurial core (60ee2593a270)
$ cd "`dirname "$TESTDIR"`"
run flake8 if it exists; if it doesn't, then just skip
$ hg files -0 'set:(**.py or grep("^#!.*python")) - removed()' \
> -X hgext3rd/evolve/thirdparty \
> 2>/dev/null \
> | xargs -0 flake8