Dockerfile first draft - DO NOT MERGE

[dsperling]

I tried to wrap the fedora-swift build scripts in a Docker image. Things work smoothly until ./swiftbuild.sh build returns:

build
~/tmp/swiftbuild/swift /fedora-swift
utils/build-script: note: using preset 'buildbot_linux_build_fedora23', which expands to 

utils/build-script --assertions --release --llbuild --swiftpm --xctest --build-subdir=buildbot_linux --lldb --release --test --validation-test --foundation -- --swift-enable-ast-verifier=0 --install-swift --install-lldb --install-llbuild --install-swiftpm --install-xctest --install-prefix=/usr '--swift-install-components=compiler;clang-builtin-headers;stdlib;sdk-overlay;dev' --build-swift-static-stdlib=1 --skip-test-lldb=1 --install-destdir=/root/tmp/swiftbuild/package --installable-package=/root/tmp/swiftbuild/package/swift-linux-x86_64-fedora-2017-02-01--18:44:14.tgz --verbose-build=1 --build-args=-j2 --install-foundation --reconfigure

utils/build-script: fatal error: can't find clang (please install clang-3.5 or a later version)
utils/build-script: fatal error: command terminated with a non-zero exit status 1, aborting

Clang does appear to be installed, so I am wondering if there is a missing clang command line parameter on utils/build-script

[makadaw]

Hi, check if you have which package installed. Build script use it to check is clang installed