[engine] All Linux builds default to building GLFW (X11 dep)

[jwinarske]

Yesterday 32-bit arm engine builds started failing

../../third_party/glfw/src/monitor.c -o obj/third_party/glfw/src/glfw.monitor.o
| In file included from ../../third_party/glfw/src/monitor.c:28:
| In file included from ../../third_party/glfw/src/internal.h:169:
| ../../third_party/glfw/src/x11_platform.h:36:10: fatal error: 'X11/Xlib.h' file not found
| #include <X11/Xlib.h>
|          ^~~~~~~~~~~~
| 1 error generated.

Master

Looks like glfw client has been enabled by default. This is the only scenario that does this. It should default to not building glfw client. X11 is not always available nor desirable.

Complete build log available here:
https://github.com/meta-flutter/meta-flutter/runs/4613236435?check_suite_focus=true

[darshankawar]

Labeling it for further input from the team.

/cc @stuartmorgan

[stuartmorgan-g]

This isn't coming from the GLFW Linux embedding, it's the engine example.

[jwinarske]

Someone checked something in two days ago that affected this. I run nightly builds and it looks like the glfw client (example) started getting built by default. This shouldn't be the case.

[stuartmorgan-g]

Presumably it was flutter/engine#30442

[jwinarske]

Yep.

@chinmaygarde this should not build by default. It's dependent on X11 even though glfw can be built for others. Also glfw sucks for embedded Linux as it requires lots of rework...