hub and __git_ps1 are slow

gistfile1.txt

[18:12:58 app (feature/403 $ u=)]$ time __git_ps1
 (feature/403 $ u=)
real    0m0.072s
user    0m0.037s
sys     0m0.033s
[18:13:18 app (feature/403 $ u=)]$ which hub
hub is /usr/local/bin/hub
[18:13:32 app (feature/403 $ u=)]$ which git
git is /usr/local/bin/git
git is /usr/bin/git
[18:13:34 app (feature/403 $ u=)]$ eval "$(hub alias -s)"
[18:13:45 app (feature/403 $ u=)]$ time __git_ps1
 (feature/403 $ u=)
real    0m0.472s
user    0m0.340s
sys     0m0.118s