Build is quite badly broken
On a recent commit I get the following build failure
ghc_gdb/ghc_heap.py:208: error:(B (B"Ptr"(B has no attribute (B"cast"(B(B
ghc_gdb/ghc_heap.py:213: error:(B (B"Ptr"(B has no attribute (B"cast"(B(B
ghc_gdb/ghc_heap.py:214: error:(B (B"Ptr"(B has no attribute (B"cast"(B(B
Found 3 errors in 1 file (checked 12 source files)(B
Also using the nix files in the gdb subdirectory directly fails because of the {nixpkgs ? nixpkgs}
argument causing infinite recursion.
ecd0a23e seems to build ok.