Issue deploying to fly.io

[cbh123]

Hi! Awesome work. This works perfectly for me when I run it locally. However, when I try and push to fly.io, I get this error:

Error happened while installing hnswlib from precompiled binary: "precompiled \"hnswlib-nif-2.17-x86_64-linux-gnu-0.1.0.tar.gz\" does not exist or cannot download: :enoent".

Any idea why that is? Any pointers would be very appreciated!

[cbh123]

With the latest release, I get a step further (thank you!). But I'm now seeing a missing checksum file when I deploy:

#0 44.63 Error happened while installing hnswlib from precompiled binary: "missing checksum.exs file".

Full error:

#0 44.28 Downloading precompiled NIF to /root/.cache/hnswlib-nif-2.17-x86_64-linux-gnu-0.1.2.tar.gz
#0 44.63 Error happened while installing hnswlib from precompiled binary: "missing checksum.exs file".
#0 44.63 
#0 44.63 Attempting to compile hnswlib from source...
#0 44.64 /bin/sh: 4: cmake: not found
#0 44.64 incomplete build of hnswlib found in '/app/_build/prod/lib/hnswlib/cmake_hnswlib', please delete that directory and retry
#0 44.64 make: *** [Makefile:37: /app/_build/prod/lib/hnswlib/priv/hnswlib_nif.so] Error 1
#0 44.64 could not compile dependency :hnswlib, "mix compile" failed. Errors may have been logged above. You can recompile this dependency with "mix deps.compile hnswlib --force", update it with "mix deps.update hnswlib" or clean it with "mix deps.clean hnswlib"