没有为自制软件找到gpg-agent

$brew install gpg-agent
Error: No available formula with the name "gpg-agent"
==> Searching for a previously deleted formula (in the last month)...
Warning: homebrew/core is shallow clone. To get complete history run:
  git -C "$(brew --repo homebrew/core)" fetch --unshallow

Error: No previously deleted formula found.
==> Searching for similarly named formulae...
Error: No similarly named formulae found.
==> Searching taps...
==> Searching taps on GitHub...
Error: No formulae found in taps.

但是,似乎此公式仍然有效：https://formulae.brew.sh/formula/gpg-agent

有没有我错误配置的东西？其他公式按预期工作(例如brew install gpg,brew install pinentry-mac).

如果此信息有用：

$brew doctor
Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: Unbrewed dylibs were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae,and may need to be deleted.

Unexpected dylibs:
  /usr/local/lib/libtcl8.6.dylib
  /usr/local/lib/libtk8.6.dylib

Warning: Unbrewed header files were found in /usr/local/include.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae,and may need to be deleted.

Unexpected header files:
  /usr/local/include/fakemysql.h
  /usr/local/include/fakepq.h
  /usr/local/include/fakesql.h
  /usr/local/include/itcl.h
  /usr/local/include/itcl2TclOO.h
  /usr/local/include/itclDecls.h
  /usr/local/include/itclInt.h
  /usr/local/include/itclIntDecls.h
  /usr/local/include/itclMigrate2TclCore.h
  /usr/local/include/itclTclIntStubsFcn.h
  /usr/local/include/mysqlStubs.h
  /usr/local/include/odbcStubs.h
  /usr/local/include/pqStubs.h
  /usr/local/include/tcl.h
  /usr/local/include/tclDecls.h
  /usr/local/include/tclOO.h
  /usr/local/include/tclOODecls.h
  /usr/local/include/tclPlatDecls.h
  /usr/local/include/tclThread.h
  /usr/local/include/tclTomMath.h
  /usr/local/include/tclTomMathDecls.h
  /usr/local/include/tdbc.h
  /usr/local/include/tdbcDecls.h
  /usr/local/include/tdbcInt.h
  /usr/local/include/tk.h
  /usr/local/include/tkDecls.h
  /usr/local/include/tkPlatDecls.h

Warning: Unbrewed .pc files were found in /usr/local/lib/pkgconfig.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae,and may need to be deleted.

Unexpected .pc files:
  /usr/local/lib/pkgconfig/tcl.pc
  /usr/local/lib/pkgconfig/tk.pc

Warning: Unbrewed static libraries were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae,and may need to be deleted.

Unexpected static libraries:
  /usr/local/lib/libtclstub8.6.a
  /usr/local/lib/libtkstub8.6.a

Warning: You have unlinked kegs in your Cellar
Leaving kegs unlinked can lead to build-trouble and cause brews that depend on
those kegs to fail to run properly once built. Run `brew link` on these:
  nmap

Warning: Homebrew's sbin was not found in your PATH but you have installed
formulae that put executables in /usr/local/sbin.
Consider setting the PATH for example like so
  echo 'export PATH="/usr/local/sbin:$PATH"' >> ~/.bash_profile

$brew config
HOMEBREW_VERSION: 1.7.5
ORIGIN: https://github.com/Homebrew/brew
HEAD: d639559c4de48faad79d3ecb1ec84dc851ea66f2
Last commit: 3 days ago
Core tap ORIGIN: https://github.com/Homebrew/homebrew-core
Core tap HEAD: bd29bc2b97641173dbe4e5ec2a6fe484dfa9dd93
Core tap last commit: 2 hours ago
HOMEBREW_PREFIX: /usr/local
HOMEBREW_GIT: git
CPU: octa-core 64-bit kabylake
Homebrew Ruby: 2.3.7 => /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/bin/ruby
Clang: 10.0 build 1000
Git: 2.19.0 => /usr/local/bin/git
Curl: 7.54.0 => /usr/bin/curl
Java: N/A
macOS: 10.13.6-x86_64
CLT: 9.4.0.0.1.1526532315
Xcode: 10.0
XQuartz: N/A