Fix for Windows to replace backslashes in paths

[nicolaspopravka]

Description of Change(s)

In the build script, replace backslashes in filepaths with forward slashes, before evoking cmake with -D argument.

Fixes Issue(s)

• On Windows, downstream projects (i.e. those with find_package(pxr CONFIG REQUIRED) calls in their CMakeLists.txt files) could fail to build with the following error:

>  cmake -DCMAKE_PREFIX_PATH="C:\Users\nicolas.popravka\AppData\Local\Programs\USD" ...
...
CMake Error at C:/Users/nicolas.popravka/AppData/Local/Programs/USD/pxrConfig.cmake:26 (if):
  Syntax error in cmake code at

    C:/Users/nicolas.popravka/AppData/Local/Programs/USD/pxrConfig.cmake:26

  when parsing string

    C:\Users\nicolas.popravka\AppData\Local\Programs\Python\Python39\python.exe

  Invalid character escape '\U'.
Call Stack (most recent call first):
  CMakeLists.txt:17 (find_package)


-- Configuring incomplete, errors occurred!

This is fixed with the proposed change.

• I have verified that all unit tests pass with the proposed changes

• I have submitted a signed Contributor License Agreement

[spitzak]

Maybe GetPythonInfo() should be fixed instead.

[sunyab]

Filed as internal issue #USD-7776

[sunyab]

Hello, I just wanted to mention that I am currently testing an alternate fix that modifies pxrConfig.cmake itself. This would fix the issue for anyone building via build_usd.py as well as users running CMake and building manually. If all goes well, this fix should be available with the next push to dev.

[sunyab]

The fix I mentioned landed in the dev branch as a7fd465, so I'm going to close this out. Please reopen or file a new issue if this doesn't seem to fix the issue you ran into. Thanks!