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     StateVar-1.2
Starting     cabal-doctest-1.0.8
Starting     ghc-paths-0.1.0.12
Starting     base-orphans-0.8.1
Building     StateVar-1.2
Building     cabal-doctest-1.0.8
Building     base-orphans-0.8.1
Completed    base-orphans-0.8.1
Starting     ghc-source-gen-0.3.0.0
Completed    StateVar-1.2
Starting     lens-family-core-2.0.0
Building     ghc-source-gen-0.3.0.0
Building     lens-family-core-2.0.0
Building     ghc-paths-0.1.0.12
Completed    cabal-doctest-1.0.8
Starting     primitive-0.7.0.0
Building     primitive-0.7.0.0
Completed    ghc-paths-0.1.0.12
Starting     random-1.1
Building     random-1.1
Completed    lens-family-core-2.0.0
Starting     tagged-0.8.6
Building     tagged-0.8.6
Completed    ghc-source-gen-0.3.0.0
Starting     th-abstraction-0.3.1.0
Building     th-abstraction-0.3.1.0
Completed    random-1.1
Starting     transformers-compat-0.6.5
Building     transformers-compat-0.6.5
Completed    tagged-0.8.6
Starting     contravariant-1.5.2
Building     contravariant-1.5.2
Completed    transformers-compat-0.6.5
Starting     lens-family-2.0.0
Completed    th-abstraction-0.3.1.0
Starting     distributive-0.6.1
Building     lens-family-2.0.0
Completed    contravariant-1.5.2
Starting     exceptions-0.10.3
Building     exceptions-0.10.3
Building     distributive-0.6.1
Completed    lens-family-2.0.0
Completed    primitive-0.7.0.0
Starting     vector-0.12.0.3
Building     vector-0.12.0.3
Completed    distributive-0.6.1
Starting     comonad-5.0.5
Completed    exceptions-0.10.3
Starting     temporary-1.3
Building     temporary-1.3
Completed    temporary-1.3
Building     comonad-5.0.5
Completed    comonad-5.0.5
Starting     bifunctors-5.5.5
Building     bifunctors-5.5.5
Completed    bifunctors-5.5.5
Starting     profunctors-5.5
Building     profunctors-5.5
Completed    profunctors-5.5
Completed    vector-0.12.0.3
Starting     proto-lens-0.6.0.0
Building     proto-lens-0.6.0.0
Completed    proto-lens-0.6.0.0
Starting     proto-lens-runtime-0.6.0.0
Building     proto-lens-runtime-0.6.0.0
Completed    proto-lens-runtime-0.6.0.0
Starting     proto-lens-protoc-0.6.0.0
Building     proto-lens-protoc-0.6.0.0
Completed    proto-lens-protoc-0.6.0.0
Starting     proto-lens-setup-0.4.0.3
Building     proto-lens-setup-0.4.0.3
Completed    proto-lens-setup-0.4.0.3
Starting     proto-lens-protobuf-types-0.6.0.0
Building     proto-lens-protobuf-types-0.6.0.0
Failed to install proto-lens-protobuf-types-0.6.0.0
Build log ( /home/builder/.cabal/logs/ghc-8.6.3/proto-lens-protobuf-types-0.6.0.0-LEDJJGYMbplLCM0zHUqPvW.log ):
cabal: Entering directory '/tmp/cabal-tmp-17203/proto-lens-protobuf-types-0.6.0.0'
[1 of 1] Compiling Main             ( /tmp/cabal-tmp-17203/proto-lens-protobuf-types-0.6.0.0/dist/setup/setup.hs, /tmp/cabal-tmp-17203/proto-lens-protobuf-types-0.6.0.0/dist/setup/Main.o )
Linking /tmp/cabal-tmp-17203/proto-lens-protobuf-types-0.6.0.0/dist/setup/setup ...
Configuring proto-lens-protobuf-types-0.6.0.0...
==========
Error: couldn't find the executable "protoc" in your $PATH.
    Follow the installation instructions at https://google.github.io/proto-lens/installing-protoc.html .
==========
Missing executable "protoc"
CallStack (from HasCallStack):
  error, called at src/Data/ProtoLens/Setup.hs:371:13 in proto-lens-setup-0.4.0.3-H0RiGm1FlIeBp8OViKkHe9:Data.ProtoLens.Setup
cabal: Leaving directory '/tmp/cabal-tmp-17203/proto-lens-protobuf-types-0.6.0.0'
cabal: Error: some packages failed to install:
proto-lens-protobuf-types-0.6.0.0-LEDJJGYMbplLCM0zHUqPvW failed during the
building phase. The exception was:
ExitFailure 1