nimble install c2nim --verbose

sherjilozair-2:~ sherjil$ nimble install c2nim --verbose
    Reading official package list
Downloading https://github.com/nim-lang/c2nim using git
    Setting Nim stdlib prefix to
    Setting Nim stdlib path to /Users/sherjil/.choosenim/toolchains/nim-#devel/lib
   Warning: Package 'c2nim' has an incorrect structure. The top level of the package source directory should contain at most one module, named 'c2nim.nim', but a file named 'rules.nim' was found. This will be an error in the future.
      Hint: If this is the primary source file in the package, rename it to 'c2nim.nim'. If it's a source file required by the main module, or if it is one of several modules exposed by 'c2nim', then move it into a 'c2nimpkg/' subdirectory. If it's a test file or otherwise not required to build the the package 'c2nim.nim', prevent its installation by adding `skipFiles = @["rules.nim"]` to the .nimble file. See https://github.com/nim-lang/nimble#libraries for more info.
    Setting Nim stdlib prefix to
    Setting Nim stdlib path to /Users/sherjil/.choosenim/toolchains/nim-#devel/lib
  Verifying dependencies for [email protected]
    Reading official package list
   Checking for compiler@#604a15c0aaf6d3df2
      Info: Dependency on compiler@#604a15c0aaf6d3df2 already satisfied
    Setting Nim stdlib prefix to
    Setting Nim stdlib path to /Users/sherjil/.choosenim/toolchains/nim-#devel/lib
  Verifying dependencies for compiler@#604a15c0aaf6d3df2
 Installing [email protected]
   Building c2nim/c2nim using c backend
     Error: Build failed for package: c2nim
        ... Details:
        ... Execution failed with exit code 1
        ... Command: "/Users/sherjil/.nimble/bin/nim" c --noBabelPath -d:release --path:"/Users/sherjil/.nimble/pkgs/compiler-#604a15c0aaf6d3df2"  -o:"/tmp/nimble_35524/githubcom_nimlangc2nim/c2nim" "/tmp/nimble_35524/githubcom_nimlangc2nim/c2nim.nim"
        ... Output: Hint: used config file '/Users/sherjil/.choosenim/toolchains/nim-#devel/config/nim.cfg' [Conf]
        ... Hint: system [Processing]
        ... Hint: c2nim [Processing]
        ... Hint: strutils [Processing]
        ... Hint: parseutils [Processing]
        ... Hint: math [Processing]
        ... Hint: algorithm [Processing]
        ... Hint: os [Processing]
        ... Hint: times [Processing]
        ... Hint: posix [Processing]
        ... Hint: ospaths [Processing]
        ... Hint: parseopt [Processing]
        ... Hint: llstream [Processing]
        ... Hint: ast [Processing]
        ... Hint: msgs [Processing]
        ... Hint: options [Processing]
        ... Hint: strtabs [Processing]
        ... Hint: hashes [Processing]
        ... Hint: osproc [Processing]
        ... Hint: streams [Processing]
        ... Hint: cpuinfo [Processing]
        ... Hint: kqueue [Processing]
        ... Hint: sets [Processing]
        ... Hint: tables [Processing]
        ... Hint: ropes [Processing]
        ... Hint: platform [Processing]
        ... Hint: terminal [Processing]
        ... Hint: macros [Processing]
        ... Hint: strformat [Processing]
        ... Hint: unicode [Processing]
        ... Hint: colors [Processing]
        ... Hint: termios [Processing]
        ... Hint: nversion [Processing]
        ... Hint: securehash [Processing]
        ... Hint: idents [Processing]
        ... Hint: wordrecg [Processing]
        ... Hint: intsets [Processing]
        ... Hint: idgen [Processing]
        ... Hint: renderer [Processing]
        ... Hint: lexer [Processing]
        ... Hint: nimlexbase [Processing]
        ... Hint: clex [Processing]
        ... clex.nim(107, 15) Error: undeclared identifier: 'FileIndex'

versions

sherjilozair-2:~ sherjil$ nim --version
Nim Compiler Version 0.18.1 [MacOSX: amd64]
Copyright (c) 2006-2018 by Andreas Rumpf

active boot switches: -d:release
sherjilozair-2:~ sherjil$ nimble --version
nimble v0.8.10 compiled at 2018-04-29 05:01:48
git hash: c249f9b83693f1623c982bb505b319248c1635bf
sherjilozair-2:~ sherjil$ choosenim show
   Channel: stable
   Version: #devel
      Path: /Users/sherjil/.choosenim/toolchains/nim-#devel