Question

So I wanted to build https://github.com/baldo/lambdacat on win.

Can’t build happy (it is on instructions) on Windows. Here is a log :

C:\Program Files\Haskell Platform\lambdacat>cabal install happy
Resolving dependencies...
[1 of 1] Compiling Main             ( C:\Users\MyUSER\AppData\Local\Temp\h
appy-1.18.6896\happy-1.18.6\Setup.lhs, C:\Users\MyUSER.BAC\AppData\Local\Temp\
happy-1.18.6896\happy-1.18.6\dist\setup\Main.o )

C:\Users\MyUSER.BAC\AppData\Local\Temp\happy-1.18.6896\happy-1.18.6\Setup.lhs:
6:52:
    Warning: In the use of `buildVerbose'
             (imported from Distribution.Simple.Setup):
             Deprecated: "Use buildVerbosity instead"

C:\Users\MyUSER.BAC\AppData\Local\Temp\happy-1.18.6896\happy-1.18.6\Setup.lhs:
7:52:
    Warning: In the use of `defaultUserHooks'
             (imported from Distribution.Simple):
             Deprecated: "Use simpleUserHooks or autoconfUserHooks, unless you n
eed Cabal-1.2
             compatibility in which case you must stick with defaultUserHooks"
Linking C:\Users\MyUSER.BAC\AppData\Local\Temp\happy-1.18.6896\happy-1.18.6\di
st\setup\setup.exe ...
Warning: defaultUserHooks in Setup script is deprecated.
Configuring happy-1.18.6...
setup.exe: The program perl is required but it could not be found.
cabal: Error: some packages failed to install:
happy-1.18.6 failed during the configure step. The exception was:
ExitFailure 1

When I try to cabal install lambdacat directly I got very bad log end

cabal: Error: some packages failed to install:
cairo-0.12.0 failed during the configure step. The exception was:
ExitFailure 1
gio-0.12.0 depends on glib-0.12.0 which failed to install.
glade-0.12.0 depends on glib-0.12.0 which failed to install.
glib-0.12.0 failed during the configure step. The exception was:
ExitFailure 1
gtk-0.12.0 depends on glib-0.12.0 which failed to install.
lambdacat-0.1.1 depends on network-2.2.1.10 which failed to install.
network-2.2.1.10 failed during the configure step. The exception was:
ExitFailure 1
pango-0.12.0 depends on glib-0.12.0 which failed to install.
webkit-0.12.1 depends on glib-0.12.0 which failed to install.

Answer 1

setup.exe: The program perl is required but it could not be found.

You need to install Perl. ActiveState has a distribution for Windows.