[vcpkg] powershell-core is required by vcpkg_copy_tool_dependencies on non-Windows, but doesn't make powershell-core available

[abique]

Host Environment

• Archlinux (up to date as of 02/11/2020)
• Compiler: gcc (GCC) 10.2.0

To Reproduce
Steps to reproduce the behavior:
./vcpkg --triplet x64-linux install cairo

Failure logs

20-11-02 18:07:38 abique@knot:~/d/vcpkg git:master> ./vcpkg --triplet x64-linux install cairo
Computing installation plan...
The following packages will be built and installed:
  * brotli[core]:x64-linux
  * bzip2[core]:x64-linux
    cairo[core]:x64-linux
  * dirent[core]:x64-linux
  * expat[core]:x64-linux
  * fontconfig[core]:x64-linux
  * freetype[bzip2,core,png]:x64-linux
  * libiconv[core]:x64-linux
  * libpng[core]:x64-linux
  * pixman[core]:x64-linux
Additional packages (*) will be modified to complete this operation.
Detecting compiler hash for triplet x64-linux...
Starting package 1/10: brotli:x64-linux
Building package brotli[core]:x64-linux...
Could not locate cached archive: /home/abique/.cache/vcpkg/archives/d4/d4e29d565a5af427af69da25079f3fe8be3f0803.zip
-- Using cached /home/abique/develop/vcpkg/downloads/google-brotli-e61745a6b7add50d380cfd7d3883dd6c62fc2c71.tar.gz
-- Cleaning sources at /home/abique/develop/vcpkg/buildtrees/brotli/src/6c62fc2c71-a8c4ea9278.clean. Use --editable to skip cleaning for the packages you specify.
-- Extracting source /home/abique/develop/vcpkg/downloads/google-brotli-e61745a6b7add50d380cfd7d3883dd6c62fc2c71.tar.gz
-- Applying patch install.patch
-- Applying patch fix-arm-uwp.patch
-- Applying patch pkgconfig.patch
-- Using source at /home/abique/develop/vcpkg/buildtrees/brotli/src/6c62fc2c71-a8c4ea9278.clean
-- Configuring x64-linux-dbg
-- Configuring x64-linux-rel
-- Building x64-linux-dbg
-- Building x64-linux-rel
CMake Error at scripts/cmake/vcpkg_copy_tool_dependencies.cmake:22 (message):
  Could not find PowerShell Core; please open an issue to report this.
Call Stack (most recent call first):
  ports/brotli/portfile.cmake:23 (vcpkg_copy_tool_dependencies)
  scripts/ports.cmake:135 (include)


Error: Building package brotli:x64-linux failed with: BUILD_FAILED
Please ensure you're using the latest portfiles with `./vcpkg update`, then
submit an issue at https://github.com/Microsoft/vcpkg/issues including:
  Package: brotli:x64-linux
  Vcpkg version: 2020.06.15-unknownhash

Additionally, attach any relevant sections from the log files above.
20-11-02 18:08:02 1 abique@knot:~/d/vcpkg git:master> 

Additional context
I don't know why it is looking for PowerShell.

[ASxa86]

Can confirm I am seeing this on CentOS 7 as well.

[abique]

This issue was introduced by: b7056e9

[BillyONeal]

It's looking for powershell because the applocal.ps1 which tries to determine what each tool depends on to copy the right associated binaries over, is a powershell script.

It looks like that test has been broken "forever"; find_program doesn't create a FOO-NOTFOUND variable, it puts FOO-NOTFOUND into that variable. Looks like that bug comes all the way back from 634c104 -- there the "if (POWERSHELL-NOTFOUND)" branch is dead. In a6a1722 I changed it to try to use an installed pwsh if that is already present, but I didn't fix that "the branch is dead" bug, and in b7056e9 I fixed the branch to not be dead. But maybe the branch should have been dead?

Even though that was wrong, because vcpkg_copy_tools_dependencies looks for ".exe", it never tried to invoke that powershell script on most *nix systems,

It passes in our CI because we have powershell core installed in our test VMs, so find_program finds it, and everything is OK.

Possible options:

• We could make this function do nothing on non-Windows which will make the message go away
• We could make sure that powershell core is acquired first by vcpkg; some ports assume powershell is available
• We could change this bit to use vcpkg_find_acquire_program to get powershell.

[BillyONeal]

I have submitted the "do nothing on non-Windows" change #14366

[abique]

Thank you @BillyONeal I'll check the master again maybe today.

[abique]

Also if a package needs powershell it should mention it in its metadata/build dependencies and vcpkg should acquire powershell I think.

[BillyONeal]

Also if a package needs powershell it should mention it in its metadata/build dependencies and vcpkg should acquire powershell I think.

On Windows it's an assumed dependency:

https://github.com/microsoft/vcpkg/blob/master/toolsrc/src/vcpkg/build.cpp#L340