I am having a very difficult time getting in-tree builds of Flang working. My build commands are as follows:
cmake -G Ninja -DLLVM_ENABLE_PROJECTS=“flang” -DCMAKE_INSTALL_PREFIX=$(pwd) -DCMAKE_BUILD_TYPE=MinSizeRel …/llvm
cmake --build . --target check-flang
cmake --build . --target install
The build itself completes successfully, and all the Flang tests pass when using “check-flang”; however, “flang -v” and “flang -h” hang (it does not produce any output and has to be killed) and, when trying to compile a program, I get the error message “execvp(pgf90) failed: No such file or directory” (which fails even if I set F18_FC to gfortran or flang). I have tried building it on a few machines to no avail. I have tested both the Debug and MinSizeRel build types, used both Ninja and Unix Makefiles to build it, and tested a few different versions of GCC/G++, ultimately settling on v9.1.0. I am building from master of the llvm-project GitHub repository.
Any insights here would be appreciated, I am at a loss about what else to try here. Any other debugging suggestions or usage tips would be appreciated as well.