Permission denied using --repo with private build server

[pfiembedded]

I've had very good success running a private build server on Ubuntu latest with MoS 2.20.0, but when I use --repo to point to local mongoose-os repo, I get permission denied when linking:

mos build --server http://192.168.50.215:8000 --repo /Users/pfiembedded/mongoose-os

[100%] Linking CXX executable pfiembedded-firmware.elf
Error running link command: Permission denied
make[3]: *** [CMakeFiles/pfiembedded-firmware.elf.dir/build.make:349: pfiembedded-firmware.elf] Error 2
make[2]: *** [CMakeFiles/Makefile2:1337: CMakeFiles/pfiembedded-firmware.elf.dir/all] Error 2
make[1]: *** [Makefile:91: all] Error 2
make: *** [/mongoose-os/platforms/esp32xx/Makefile.build:219: /var/tmp/fwbuild-volumes/2.20.0/apps/pfiembedded-firmware/esp32/build_contexts/build_ctx_316702948/build/objs/pfiembedded-firmware.bin] Error 2
make: Leaving directory '/app'
Error: exit status 2
/src/cli/build_local.go:692: 
/src/cli/build_local.go:679: 
/src/cli/build_local.go:444: 
/src/cli/build.go:278: 
/src/cli/build.go:143: 
/src/cli/main.go:194: build failed
Error: /private/tmp/mos-20221214-7434-ltqdk0/mos-0278853cf62da0c96ef239143243e854b2f611a8/cli/build_remote.go:359: build failed
/private/tmp/mos-20221214-7434-ltqdk0/mos-0278853cf62da0c96ef239143243e854b2f611a8/cli/build.go:278: 
/private/tmp/mos-20221214-7434-ltqdk0/mos-0278853cf62da0c96ef239143243e854b2f611a8/cli/build.go:221: 
/private/tmp/mos-20221214-7434-ltqdk0/mos-0278853cf62da0c96ef239143243e854b2f611a8/cli/main.go:194: build failed