Brew cannot find the installed gpg binary

[Moulick]

Output of brew config

HOMEBREW_VERSION: 4.1.5-55-g3cd7290
ORIGIN: https://github.com/Homebrew/brew
HEAD: 3cd72905ce3d36a84994cc6c6b9ebbdafff4e922
Last commit: 3 days ago
Core tap origin: https://github.com/Homebrew/homebrew-core
Core tap HEAD: 23d49413bd4dd2223b2b172fae8ec49c304179c6
Core tap last commit: 38 minutes ago
Core tap branch: bump-stern-1.26.0
Core tap JSON: 21 Aug 08:26 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_EDITOR: code --wait
HOMEBREW_GITHUB_API_TOKEN: set
HOMEBREW_MAKE_JOBS: 8
Homebrew Ruby: 2.6.10 => /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby
CPU: octa-core 64-bit arm_firestorm_icestorm
Clang: 14.0.3 build 1403
Git: 2.41.0 => /opt/homebrew/bin/git
Curl: 8.1.2 => /usr/bin/curl
macOS: 13.5.1-arm64
CLT: 14.3.1.0.1.1683849156
Xcode: N/A
Rosetta 2: false

Output of brew doctor

Your system is ready to brew.

Description of issue

While running brew bump --open-pr <formula>, brew is unable to find the gpg binary. It's unable to find any other binary like diff-so-fancy (used in my ~/.gitconfig). Both are available in /opt/homebrew/bin/

❯ brew bump --open-pr stern
==> stern
Current formula version:  1.25.0
Latest livecheck version: 1.26.0
Latest Repology version:  1.26.0
Open pull requests:       none
Closed pull requests:     none
==> Downloading https://github.com/stern/stern/archive/v1.26.0.tar.gz
Already downloaded: /Users/moulick.aggarwal/Library/Caches/Homebrew/downloads/3e738e4ca7208c3dbf625cd98bd258659f8d45fa0127ce69b18999c8c0ed1dd7--stern-1.26.0.tar.gz
Warning: Cannot verify integrity of '3e738e4ca7208c3dbf625cd98bd258659f8d45fa0127ce69b18999c8c0ed1dd7--stern-1.26.0.tar.gz'.
No checksum was provided.
For your reference, the checksum is:
  sha256 "1caf2a6f1492f763bb6a961d4c8af8cd3ab1952d216b0ab21059fe1a1d4426db"
==> replace /https:\/\/github\.com\/stern\/stern\/archive\/v1\.25\.0\.tar\.gz/ with "https://github.com/stern/stern/archive/v1.26.0.tar.gz"
==> replace "9742fa8d9c4b75bf0b261c42996d26c0f706400c043f3f83d159238326c717ea" with "1caf2a6f1492f763bb6a961d4c8af8cd3ab1952d216b0ab21059fe1a1d4426db"
diff-so-fancy | less --tabs=4 -RF: diff-so-fancy: command not found
M	Formula/s/stern.rb
Switched to a new branch 'bump-stern-1.26.0'
error: cannot run gpg: No such file or directory
error: gpg failed to sign the data:
(no gpg output)
fatal: failed to write commit object
Error: Failure while executing; `git commit --no-edit --verbose --message=stern\ 1.26.0 -- /opt/homebrew/Library/Taps/homebrew/homebrew-core/Formula/s/stern.rb` exited with 128.

❯ which gpg
/opt/homebrew/bin/gpg

❯ which diff-so-fancy
/opt/homebrew/bin/diff-so-fancy

[SMillerDev]

Is /opt/homebrew/bin in the PATH that git uses?

[Moulick]

Commit (with sign) directly works fine

  /opt/homebrew/Library/Taps/homebrew/homebrew-core   bump-stern-1.26.0 +1                                                                  11s
❯ git commit --no-edit --verbose --message=stern\ 1.26.0 -- /opt/homebrew/Library/Taps/homebrew/homebrew-core/Formula/s/stern.rb
[bump-stern-1.26.0 5880cf9c1cb] stern 1.26.0
 1 file changed, 2 insertions(+), 2 deletions(-)

[Moulick]

any further things I can try?

[SMillerDev]

I'm not sure, almost all guides I've ever seen on the subject hardcode the gpg path so I'd just recommend doing that.

[Moulick]

Defining below ~/.gitconfig works

[gpg]
  program = /opt/homebrew/bin/gpg