msbuild -test returns a false positive on Manjaro Linux

[treymerkley]

Steps to reproduce

I just ran ./build.sh -test on the msbuild directory.

Expected behavior

A clean testing with no errors, as was produced by the dev.azure testing here: https://dev.azure.com/dnceng/public/_build/results?buildId=375828&view=ms.vss-test-web.build-test-results-tab&j=a964745c-2ee7-5657-5893-57d8a23ba1c9

Actual behavior

Shouldly.ShouldAssertException : \"/usr/bin/sh\"
    should be with options: Ignoring case
\"/bin/sh\"
    but was not
    difference
Difference     |       |    |    |         |    |    |    |    |    |   
               |      \|/  \|/  \|/       \|/  \|/  \|/  \|/  \|/  \|/  
Index          | 0    1    2    3    4    5    6    7    8    9    10   
Expected Value | /    b    i    n    /    s    h                        
Actual Value   | /    u    s    r    /    b    i    n    /    s    h    
Expected Code  | 47   98   105  110  47   115  104                      
Actual Code    | 47   117  115  114  47   98   105  110  47   115  104  
   at Shouldly.ShouldBeStringTestExtensions.ExecuteAssertion(IAssertion assertion, Func`1 customMessage)
   at Microsoft.Build.UnitTests.ToolTask_Tests.FindOnPathSucceeds() in /home/trey/git/msbuild/src/Utilities.UnitTests/ToolTask_Tests.cs:line 689

Environment data

msbuild /version output:
16.0.0.0

OS info:
Manjaro Linux, latest stable

If applicable, version of the tool that invokes MSBuild (Visual Studio, dotnet CLI, etc): None, running MSBuild directly.