Versatile and reliable tool to download build deps based on manifest file
Intended for CI use

--------------------------------------------------------------------------------

(artifact
 (constant base "foment")
 (constant version "0.4.1")
 (checksum "9c6d3829e82fdadc9aa48ad4ec39f2e7c2698e49373c87f1b271b179b517267e")
 (filename "{base}.tar.gz")
 (download "https://github.com/leftmike/{base}/archive/v{version}.tar.gz")
 (directory "{base}" (extract-from "{base}-{version}")))

(artifact
 (constant base "chibi-scheme")
 (constant version "0.8.0")
 (checksum sha256 "c39287628cb7762d6cd51fbdab39e797ef7f7e576a3c7650a8a2a02b4f35749a")
 (filename "{base}.tgz")
 (download "http://synthcode.com/scheme/chibi/{base}-{version}.tgz")
 (directory "{base}" (extract-from "{base}-{version}")))

(artifact
 (constant base "femtolisp")
 (commit "ec7601076a976f845bc05ad6bd3ed5b8cde58a97")
 (download "https://github.com/JeffBezanson/{base}.git")
 (extract-directory "{base}"))

(artifact
 (constant base "stack")
 (constant version "2.1.3")
 (checksum sha256 "c724b207831fe5f06b087bac7e01d33e61a1c9cad6be0468f9c117d383ec5673")
 (download "https://get.haskellstack.org/stable/{os}-{arch}.tar.gz")
 (file "{HOME}/.local/bin/{base}"
       (extract-from "{base}-{version}-{os}-{arch}/{base}")
       (executable? #t)
       (executable-for linux x86_64)))

(artifact
 (download "https://codeclimate.com/downloads/test-reporter/"
           "test-reporter-latest-{os}-{arch}")
 (checksum sha256 "38f2442892027f61a07f52c845818750261b2ba58bffb043a582495339d37c05")
 (file "cc-test-reporter"
       (executable? #t)
       (executable-for linux x86_64)))

--------------------------------------------------------------------------------

C LIBRARIES NEEDED

- openssl/libressl
- curl (https/http/ftp)
- sha1, sha256, sha512
- gzip, bzip2, xz, zip
- libarchive
- libgit2

CODE THAT NEEDS TO BE WRITTEN

- parse spec file
- glue libraries together
- unix/windows interface
- can we interface exotic VC systems (hg/bzr/svn) via their command line tools?