adjust scripts, Cmake for OSX. Updates README

[davebryson]

Signed-off-by: Dave Bryson

Changes:

• Removed brew installs from configure.sh and added to build information in README. Why? calling sudo ./configure.sh fails as brew can't be called with sudo
• Moved OSX specific CMAKE_FLAGS to CmakeFile.txt
• Added build information to README

References: #94

[HalosGhost]

calling sudo ./configure.sh fails as brew can't be called with sudo

Does it make sense, then, to instead inline the use of sudo for the linux commands (resulting in the correct invocation for both platforms being ./scripts.configure.sh (no sudo))? This PR as-it-stands makes it so that there's an additional step for macOS (the brew install commands) beyond what's necessary for linux (which, in an ideal world, I think we should try to avoid).

Additionally, it looks like this PR includes some trailing whitespace in a few files (namely, CMakeLists.txt, and README.md) which is why the lint CI check failed.

[davebryson]

@HalosGhost Thanks for the feedback. Resolving the linting issues now.

As for sudo, this is something I went back and forth on a couple of times. I even attempted having cmake install leveldb and nuraft to eliminate the need for sudo. But in the end, I settled on the path of least resistance (for now) so as not to cause a ripple effect with ci.yml etc... I'm open to suggestions... There's definitely room for improvement. For example, OSX is using leveldb from brew that's a different version than the one used by the linux build. And is llvm@11 a brew dependency solely for clang-tidy and clang-format?

[jonwiggins]

This worked for me on an M1 Mac. Although at first after following the steps when I ran ./scripts/build.sh, I got:

CMake Error at CMakeLists.txt:4 (project):
  The CMAKE_C_COMPILER:

    /Applications/Xcode.app/Contents/Developer/usr/bin/clang

  is not a full path to an existing compiler tool.

I had to run

sudo xcode-select -switch /Library/Developer/CommandLineTools

And then everything worked.

[HalosGhost]

sudo xcode-select -switch /Library/Developer/CommandLineTools

This might make sense to include in the README in the macOS instructions. @davebryson what do you think?

[davebryson]

@HalosGhost Maybe xcode-select --install would be better to make sure it's installed. I believe installing it will automatically set the path.

[jonwiggins]

@HalosGhost Maybe xcode-select --install would be better to make sure it's installed. I believe installing it will automatically set the path.

I had already installed it, it looks like the issue can be caused by:

1. Installing other programs which mess with the path: https://stackoverflow.com/questions/17980759/xcode-select-active-developer-directory-error
2. Updating macOS: https://developer.apple.com/forums/thread/666584

[AlexRamRam]

Add cmake to brew install list

[AlexRamRam]

My apologies for the multiple reviews (open-source/GH newbie ...)

[HalosGhost]

@davebryson I took another look, and Alex has had occasion to do another clean build using your changes, and they all look set. Can you squash a single commit, and then I shall merge it?

[HalosGhost]

@davebryson it looks like you merged back in from trunk, but didn't squash (resulting in 10 commits to pull rather than 1).

[davebryson]

@HalosGhost Yea I pulled to merge the latest by accident. But haven't done the squash yet. Sorry for the mis-leading message

[davebryson]

@HalosGhost Squash is done. I had to back out the latest merges from dci/trunk.

[HalosGhost]

@davebryson these changes look solid and I'm ready to merge but I just wanted to double-check one thing with you. You've included a DCO sign-off, so as far as we're concerned, this is set from an IP perspective. However, because your sign-off isn't at the end of the commit message, git isn't aware of it:

$ git interpret-trailers --parse <this-commit-as-a-patch-file>
$

This might mean that you're not credited appropriately for the commit. If you're worried about that, you can amend the commit message so that the sign-off is in its own paragraph at the end of the commit message (contiguously with any other trailers):

Support for OSX Build

Updated scripts, cmake, and README for building on OSX

Signed-off-by: Dave Bryson <daveb@miceda.org>

Which git understands correctly:

$ git interpret-trailers --parse <the-updated-commit-patch>
Signed-off-by: Dave Bryson <daveb@miceda.org>

Feel free to push the amended commit if you want to fix it; otherwise, ping me and I'll merge!

[HalosGhost]

Conferred offline; @davebryson asked for it to be merged.