cloud-microphysics/setup.sh fails when ~/.local/lib/pkgconfig is missing

On macOS with no `~./local/lib/pkgconfig` directory, executing
```
git clone git@github.com:berkeleylab/inference-engine
cd inference-engine
./setup
```
completes and all tests pass.  However, 
```
cd cloud-microphysics
./setup.sh
```
yields the following trailing output:
```
realpath: /Users/rouson/.local/lib/pkgconfig: No such file or directory
```