Missing extern_parameters.cpp when compiling burn_cell in DEBUG mode

[chongchonghe]

I am trying compile and run the burn_cell unit test in debug mode but got this error:

make: *** No rule to make target `extern_parameters.cpp', needed by `tmp_build_dir/o/3d.gnu.DEBUG.EXE/extern_parameters.o'.  Stop.

steps to reproduce the bug:

1. run

export AMREX_HOME=/path/to/amrex
cd unit_test/burn_cell
make DEBUG=TRUE

2. see the error.

[zingale]

just to be clear -- you replaces /path/to/amrex to the actual path to the amrex/ directory on your system?

[chongchonghe]

just to be clear -- you replaces /path/to/amrex to the actual path to the amrex/ directory on your system?

Yes, for sure.

After some experiment, I found the following behaviors:

1. This error did not happen the first time I compile the burn_cell test, but I happens every time I do make clean followed by make. However, when this happens, extern_parameters.cpp actually exists in /tmp_build_dir/microphysics_sources/3d.gnu.EXE/extern_parameters.cpp.
2. After this error happens, I run another make, and it successfully compiles.
3. Same for DEBUG=TRUE or DEBUG=FALSE.

I didn't look deep into the cause of this error, but I speculate we could avoid it by using a OUTDIR parameter in make to allow compile into a specific build/ folder.

[zingale]

are you using cmake? or just make? we already use an build directory, that's what tmp_build_dir does.