System.Drawing.Common: Assert libgdiplus 6.0.1 on macOS unit tests

[qmfrederik]

This is dotnet/corefx#41707 ported to dotnet/runtime. Depends on the build servers having a recent version of libgdiplus.

[qmfrederik]

@stephentoub @safern I guess the project could use some documentation which summarizes the whole libgdiplus situation, including some of the guidelines developed in dotnet/corefx#41707 .

Happy to put forward a first draft of such a document. If you think it's useful, let me know where that document should go & what content you feel would be good to include in such a document.

[danmoseley]

Nit, do not need to initialize.

Suggested change

	Version installedVersion = null;
	Version installedVersion;

[danmoseley]

Yay cleanup. You'll want to check, of course, that on our macOS machines these tests actually run.

Not sure how, since the only results available in the CI logs are the failures. Perhaps you could push a change that reverses the sense, and verify they fail.

edit: whoops, I missed that you assert it. Fine.

[safern]

Thanks!

[ericstj]

/azp run runtime-libraries

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[safern]

I just pinged: https://github.com/dotnet/core-eng/issues/7268

[stephentoub]

@safern, any updates here? Doesn't seem to be any progress on the linked issue.

[safern]

Let me poke around.

[safern]

@qmfrederik I've asked @MattGal and the team working on updating the machines said they're ready. Would you mind fixing the merge conflicts so that we get a new CI build and test that?

[safern]

Hmm it seems like they still don't have 6.0.4 installed:
cc: @MattGal @ilyas1974

[MattGal]

@safern I believe I was able to determine why this is and am following up with some folks from DDFUN. Basically, the macs mostly have some combination of LigGDIPlus 5.6 and/or, broken brew, and we didn't give them the exact right instructions. Decent chance we can sort this today.

[safern]

/azp run runtime

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[safern]

/azp run runtime

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[qmfrederik]

Looks like CI passed this time 🎉

[safern]

Thanks @qmfrederik