I found a thread about it, but it seems I’m not technical enough to get it: http://lists.indexdata.dk/pipermail/yazlist/2009-October/002788.html

make: *** [install-recursive] Error 1
==> Backtrace
/usr/local/Library/Homebrew/formula.rb:242:in system' /usr/local/Library/Formula/yaz.rb:15:ininstall'
/usr/local/Library/Homebrew/install.rb:89:in install' /usr/local/Library/Homebrew/formula.rb:153:inbrew'
/usr/local/Library/Homebrew/formula.rb:290:in stage' /usr/local/Library/Homebrew/formula.rb:257:inmktemp'
/usr/local/Library/Homebrew/formula.rb:288:in stage' /usr/local/Library/Homebrew/formula.rb:148:inbrew'
/usr/local/Library/Homebrew/install.rb:76:in `install'
/usr/local/Library/Homebrew/install.rb:39
/usr/local/Library/Formula/yaz.rb:13
==> Environment
fatal: Not a git repository (or any of the parent directories): .git
HOMEBREW_VERSION: 0.5
HEAD:
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CELLAR: /usr/local/Cellar
HOMEBREW_CACHE: /Users/julian/Library/Caches/Homebrew
HOMEBREW_REPOSITORY: /usr/local
Library Path: /System/Library/Frameworks/RubyCocoa.framework/Resources/ruby
Hardware: dual-core 64-bit core2
OS X: 10.6.2
Kernel Architecture: i386
Ruby: 1.8.7-72
GCC: 4.2 build 5646
LLVM: build 2206
MacPorts or Fink? false
Exit status: 512
Error: Failure while executing: make install
Please report this bug to http://bit.ly/Homebrew