`HTTP.get()` crashes Julia completely

No, those files are automatically generated, a manual PR would be overwritten.

For a while, yes.

Not sure what “ELIF” means here. If you’re asking for an explanation, libmdetls.so depends on libmbedx509.so, as you can see with ldd ~/.julia/artifacts/746f3085962108a6a143ae685781235717cec381/lib/libmbedtls.so. In the JLL wrapper libmdetls.so is being opened before libmbedx509.so. Not finding libmbedx509.so already available, when trying to dlopen libmbedtls.so your dynamic loader decided to open the system libmbedx509.so, instead of the one from the artifacts (which is what happens in my case). By inverting the opening order you make sure that the dynamic loader doesn’t decide to open the system library.