tests: add script to disable a selected wire protocol capability
This can be used to test that the client and server both fall back to the
previous wire protocol when the capability is not supported.
It is currently used by test-push-http.t and I plan to use it for the HTTP
long argument support tests.
hg debuginstall
$ hg debuginstall
Checking encoding (ascii)...
Checking installed modules (*/mercurial)... (glob)
Checking templates...
Checking commit editor...
Checking username...
No problems detected
hg debuginstall with no username
$ HGUSER= hg debuginstall
Checking encoding (ascii)...
Checking installed modules (*/mercurial)... (glob)
Checking templates...
Checking commit editor...
Checking username...
no username supplied (see "hg help config")
(specify a username in your configuration file)
1 problems detected, please check your install!
[1]