Warning: The install command is a part of the legacy v1 style of cabal usage.

Please switch to using either the new project style and the new-install
command or the legacy v1-install alias as new-style projects will become the
default in the next version of cabal-install. Please file a bug if you cannot
replicate a working v1- use case with the new-style commands.

For more information, see: https://wiki.haskell.org/Cabal/NewBuild

Resolving dependencies...
Starting     semigroups-0.19
Starting     data-accessor-0.2.3
Starting     utility-ht-0.0.14
Building     data-accessor-0.2.3
Building     semigroups-0.19
Building     utility-ht-0.0.14
Completed    semigroups-0.19
Completed    data-accessor-0.2.3
Completed    utility-ht-0.0.14
Starting     storable-record-0.0.4
Building     storable-record-0.0.4
Completed    storable-record-0.0.4
Downloading  enumset-0.0.4.1
Downloaded   enumset-0.0.4.1
Starting     enumset-0.0.4.1
Building     enumset-0.0.4.1
Completed    enumset-0.0.4.1
Downloading  llvm-ffi-3.8.1.1
Downloaded   llvm-ffi-3.8.1.1
Starting     llvm-ffi-3.8.1.1
Failed to install llvm-ffi-3.8.1.1
Build log ( /home/builder/.cabal/logs/ghc-8.6.3/llvm-ffi-3.8.1.1-DLhT9MPfOkUGvmaGR5Q6MF.log ):
cabal: Entering directory '/tmp/cabal-tmp-28343/llvm-ffi-3.8.1.1'
Configuring llvm-ffi-3.8.1.1...
cabal: Missing dependency on a foreign library:
* Missing (or bad) C library: LLVM-3.8
This problem can usually be solved by installing the system package that
provides this library (you may need the "-dev" version). If the library is
already installed but in a non-standard location then you can use the flags
--extra-include-dirs= and --extra-lib-dirs= to specify where it is.If the
library file does exist, it may contain errors that are caught by the C
compiler at the preprocessing stage. In this case you can re-run configure
with the verbosity flag -v3 to see the error messages.

cabal: Leaving directory '/tmp/cabal-tmp-28343/llvm-ffi-3.8.1.1'
cabal: Error: some packages failed to install:
llvm-ffi-3.8.1.1-DLhT9MPfOkUGvmaGR5Q6MF failed during the configure step. The
exception was:
ExitFailure 1