Docker build failure, missing gcc

[frankinspace]

Trying to build the current Dockerfile results in an error because gcc is not found.

docker build .

...

#10 10.40             creating build/temp.linux-x86_64-3.9/dulwich
#10 10.40             gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -fPIC -I/usr/local/include/python3.9 -c dulwich/_objects.c -o build/temp.linux-x86_64-3.9/dulwich/_objects.o
#10 10.40             error: command 'gcc' failed: No such file or directory
#10 10.40             [end of output]
#10 10.40       
#10 10.40         note: This error originates from a subprocess, and is likely not a problem with pip.
#10 10.40       error: legacy-install-failure
#10 10.40       
#10 10.40       × Encountered error while trying to install package.
#10 10.40       ╰─> dulwich
#10 10.40       
#10 10.40       note: This is an issue with the package mentioned above, not pip.
#10 10.40       hint: See above for output from the failure.
#10 10.40       [end of output]
#10 10.40   
#10 10.40   note: This error originates from a subprocess, and is likely not a problem with pip.
#10 10.41 error: subprocess-exited-with-error
#10 10.41 
#10 10.41 × pip subprocess to install build dependencies did not run successfully.
#10 10.41 │ exit code: 1
#10 10.41 ╰─> See above for output.
#10 10.41 
#10 10.41 note: This error originates from a subprocess, and is likely not a problem with pip.
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executor failed running [/bin/sh -c pip install .]: exit code: 1