AppVeyor Build Failure with CMake >=3.12 about cef-binary

[amaitland]

Using advice from https://help.appveyor.com/discussions/problems/10014-false-build-fail-status I've changed how the build script is run from the AppVeyor.

The warning is now ignored and the first build using VS2019 as the default was successful.

https://ci.appveyor.com/project/cefsharp/cef-binary/builds/40187622

[amaitland]

Reverted to using the previous build worker image in commit c510ba2

Build succeeded https://ci.appveyor.com/project/cefsharp/cef-binary/build/64.0.0-CI67

[amaitland]

Builds are failing again.

[amaitland]

According to https://www.appveyor.com/docs/windows-images-software/ the version of cmake has been upgraded to 3.12.2 so appears the problem is something different than initially though.

Will test with Visual Studio 2017 Preview and see if there's any change.

[perlun]

FWIW (and I'm sure you already saw this), here is the failure. VS2017 Preview doesn't seem to help, unfortunately:

Caught an exception: Cannot bind argument to parameter 'Path' because it is null.
	Exception Type: System.Management.Automation.ParameterBindingValidationException
	Stack Trace: at Msvs, C:\projects\cef-binary\build.ps1: line 270
	at VSX, C:\projects\cef-binary\build.ps1: line 376
	at <ScriptBlock>, C:\projects\cef-binary\build.ps1: line 714
	at <ScriptBlock>, <No file>: line 1
Cannot bind argument to parameter 'Path' because it is null.

[amaitland]

Building locally now fails with the same exception, just in a different place. So it appears VS2017 15.8.8 breaks something. Will likely have to deal with that at some point

[amaitland]

Switching to latest cmake in bdfb0a0 has made no effect. Local builds are working as expected. Will have to find a way to get cmake to output more detailed info (it does running locally, that info is lost when running on appveyor).

[amaitland]

Looking closer at the local output and I see the same warning, so It's probably not the root cause. Need to get cmake error output or be able to download it's log file.

CMake Warning (dev) at CMakeLists.txt:187 (find_package):
Policy CMP0074 is not set: find_package uses <PackageName>_ROOT variables.
Run "cmake --help-policy CMP0074" for policy details.  Use the cmake_policy
command to set the policy and suppress this warning.

CMake variable CEF_ROOT is set to:

C:/projects/cef-binary/cef_binary_3.y.z_windows32

[amaitland]

Build https://ci.appveyor.com/project/cefsharp/cef-binary/builds/21030987 was successful when rolling back to cmake 3.11.4 (commit 55140b1)

It appears that CMake Policy CMP0074 writes a warning to stderr which Appveyor was treating as fatal and terminating the build.

For now build.ps1 is only usable if you have cmake.portable installed using chocolatey.

[mitchcapper]

I am not sure if we want to try and modify the cmakelist file after it's generated to add something like:

if(POLICY CMP0074)
  cmake_policy(SET CMP0074 OLD)
endif()

to disable the warning to allow it to work on Appveyor.

[amaitland]

I'd largely forgotten about this, builds have been working.

Long term it would be better to have CEF clearly define the expected behaviour and avoid the warning.

From my point of view this really isn't even on my TODO list, if the cmake requirements suddenly change then I'll do something about it.

If it's causing you problems then by all means submit a PR with a different workaround.

[amaitland]

CMake-3.14 would be required to build VS2019 with AppVeyor, if we are to look into that further then yes we'd need to implement a different workaround for this.