Build problems

[si14]

> cabal-dev install-deps                                                                                                                       master [2fd8de2] untracked
You are using a version of cabal-install that has the --only-dependencies flag
to the install command. Invoking that instead...
Resolving dependencies...
[1 of 2] Compiling SetupWrapper     ( /tmp/cairo-0.12.4-28123/cairo-0.12.4/SetupWrapper.hs, /tmp/cairo-0.12.4-28123/cairo-0.12.4/dist/setup/SetupWrapper.o )
[2 of 2] Compiling Main             ( /tmp/cairo-0.12.4-28123/cairo-0.12.4/Setup.hs, /tmp/cairo-0.12.4-28123/cairo-0.12.4/dist/setup/Main.o )
Linking /tmp/cairo-0.12.4-28123/cairo-0.12.4/dist/setup/setup ...
[1 of 2] Compiling Gtk2HsSetup      ( Gtk2HsSetup.hs, dist/setup-wrapper/Gtk2HsSetup.o )
[2 of 2] Compiling Main             ( SetupMain.hs, dist/setup-wrapper/Main.o )
Linking dist/setup-wrapper/setup ...
Cannot find gtk2hsC2hs
Please install `gtk2hs-buildtools` first and check that the install directory is in your PATH (e.g. HOME/.cabal/bin).
Failed to install cairo-0.12.4
cabal: Error: some packages failed to install:
Chart-0.16 depends on cairo-0.12.4 which failed to install.
cairo-0.12.4 failed during the configure step. The exception was:
ExitFailure 1

It's unclear from README that one needs to install gtk2hs-buildtools to build this stuff. libcairo2-dev is also needed, as it turns out, and an error is also uninformative (found with trial and error).