Resolving dependencies...
Configuring mtl-2.2.1...
Building mtl-2.2.1...
Installed mtl-2.2.1
Configuring BNFC-2.8.1...
Building BNFC-2.8.1...
Installed BNFC-2.8.1
Downloading cubical-0.1.0...
Configuring cubical-0.1.0...
Failed to install cubical-0.1.0
Build log ( /home/builder/.cabal/logs/cubical-0.1.0.log ):
cabal: Entering directory '/tmp/cabal-tmp-6836/cubical-0.1.0'
[1 of 1] Compiling Main             ( /tmp/cabal-tmp-6836/cubical-0.1.0/dist/setup/setup.hs, /tmp/cabal-tmp-6836/cubical-0.1.0/dist/setup/Main.o )
Linking /tmp/cabal-tmp-6836/cubical-0.1.0/dist/setup/setup ...
/bin/sh: 1: bnfc: not found
setup: bnfc command not found or error127
CallStack (from HasCallStack):
  error, called at /tmp/cabal-tmp-6836/cubical-0.1.0/dist/setup/setup.hs:8:22 in main:Main
cabal: Leaving directory '/tmp/cabal-tmp-6836/cubical-0.1.0'
cabal: Error: some packages failed to install:
cubical-0.1.0 failed during the configure step. The exception was:
ExitFailure 1