Install headers to include/${PROJECT_NAME}

[sloretz]

The patch is taken from this PR yaml/libyaml#244

This is in support of ros2/ros2#1150

The externalproject_add( changes are from ignition_math6_vendor.

[sloretz]

CI (build: --packages-above-and-dependencies libyaml_vendor test: --packages-select libyaml_vendor)

• Linux
• Linux-aarch64
• Windows

[clalancette]

I left one thing that I think should be changed, but this otherwise looks good to me.

[clalancette]

I'll point out that you can use an actual tag here (like 0.2.5), which I think would be preferable.

[sloretz]

I'm not sure that's preferable. Currently a URL to a zip file and an MD5 sum are used. The MD5 sum makes sure the archive contains what we expect it to (limited by the ease of which it is to make an MD5 collision these days). If GIT_TAG only says the human readable tag name, then a change to the tag upstream could break the build, or worse be a security issue. Using the sha hash solves that.

[clalancette]

We discussed this elsewhere, and we are going to switch to git hashes everywhere. So with that, I'll go ahead and approve.

[clalancette]

Looks good with green CI.

[sloretz]

CI (build: --packages-above-and-dependencies libyaml_vendor test: --packages-select libyaml_vendor)

• Linux
• Linux-aarch64
• Windows