You can bump a formula entirely on the command line.
$ brew bump-formula-pr --strict faas-cli --tag=0.4.6 --revision=39183ee1b344a7bb8825bd2ebedce5c0bf4262c4
You'll be prompted to allow access to your git credentials in the OSX keychain. There may be some extra setup required tho, possibly setting up the remote?
Already up-to-date.
==> replace "0.4.5" with "0.4.6"
==> replace "e9c738f9a2833980a1bfc0102b3dfdf0cce2684a" with "39183ee1b344a7bb8825bd2ebedce5c0bf4262c4"
==> Downloading https://homebrew.bintray.com/bottles/hub-2.2.9.sierra.bottle.tar.gz
==> Downloading from https://akamai.bintray.com/6c/6c23abd1255f04855fc1dfb8d44706337b728b5785e5b79f2319637575be93c7?__gda__=exp=150240114
######################################################################## 100.0%
==> Pouring hub-2.2.9.sierra.bottle.tar.gz
==> Caveats
Bash completion has been installed to:
/usr/local/etc/bash_completion.d
zsh completions have been installed to:
/usr/local/share/zsh/site-functions
==> Summary
🍺 /usr/local/Cellar/hub/2.2.9: 10 files, 9MB
M Formula/faas-cli.rb
Switched to a new branch 'faas-cli-0.4.6'
[faas-cli-0.4.6 6bb213e678] faas-cli 0.4.6
1 file changed, 2 insertions(+), 2 deletions(-)
Counting objects: 9043, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (2858/2858), done.
Writing objects: 100% (9043/9043), 1.95 MiB | 1.00 MiB/s, done.
Total 9043 (delta 6714), reused 8492 (delta 6179)
remote: Resolving deltas: 100% (6714/6714), completed with 836 local objects.
To github.com:johnmccabe/homebrew-core.git
* [new branch] faas-cli-0.4.6 -> faas-cli-0.4.6
Branch faas-cli-0.4.6 set up to track remote branch faas-cli-0.4.6 from johnmccabe.
Switched to branch 'master'
Your branch is up-to-date with 'origin/master'.