Got the error with minimal dub application. Steps to reproduce: ``` C:\test>dub init -n Successfully created an empty project in 'C:\test'. Package successfully created in . C:\test>dub test No source files found in configuration 'library'. Falling back to "dub -b unittest". Performing "unittest" build using C:\D\dmd2\windows\bin\dmd.exe for x86_64. test ~master: building configuration "application"... Linking... Running .\test.exe Edit source/app.d to start your project. C:\test>dub add silly Adding dependency silly ~>1.0.2 C:\test>dub test No source files found in configuration 'library'. Falling back to "dub -b unittest". Performing "unittest" build using C:\D\dmd2\windows\bin\dmd.exe for x86_64. test ~master: building configuration "application"... C:\Users\andrey\AppData\Local\dub\packages\silly-1.0.2\silly\silly.d(15,2): Error: static assert: "Couldn't find 'dub_test_root'. Make sure you are running tests with dub test" C:\D\dmd2\windows\bin\dmd.exe failed with exit code 1. ``` D tools used: ``` C:\test>dub --version DUB version 1.20.0, built on Mar 9 2020 C:\test>dmd --version DMD32 D Compiler v2.091.0-dirty Copyright (C) 1999-2020 by The D Language Foundation, All Rights Reserved written by Walter Bright ```