solaris-x86-head (Solaris/x86 HEAD (Karel Gardas)), build 536, Failure

[Builder]

solaris-x86-head (Solaris/x86 HEAD (Karel Gardas)), build 536

Build failed
Details: http://haskell.inf.elte.hu/builders/solaris-x86-head/536.html

git clone                    | Success
git clone (Windows tarballs) | Success
create mk/build.mk           | Success
repo versions                | Failure: Just (ExitFailure 1)

Build failed
Details: http://haskell.inf.elte.hu/builders/solaris-x86-head/536.html

-------------- next part --------------
Entering '.arc-linters/arcanist-external-json-linter'
85ece0f8653e7b1e7de6024d372cfeaf36ab5fa9 Don't construct intermediate dictionary
Entering 'libffi-tarballs'
fatal: ambiguous argument 'HEAD^..': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions
Stopping at 'libffi-tarballs'; script returned non-zero status.