Fix codesigning issue on x86_64-apple-darwin

[odow]

Closes #5

[simonbowly]

@odow does this indicate a problem with the signing of the Gurobi library, or is it a more general julia/mac issue?

[odow]

I have no idea. I guess not (because I can use the gurobi_cl binary). It happens to other binaries:

What do you see as the output of run(`codesign -dvv $(Gurobi_jll.libgurobi)`) on an M-series Mac?

[simonbowly]

v10 appears with an adhoc signature and v11 with no signature, which seems odd. A normal Gurobi install has a proper signature on the library, but it's also a macos universal build while the conda packages only contain one architecture. I'll check if we can improve something. Thanks for resolving it here.

[odow]

It might also be that the way we download it and unpack through Julia's Tar.jl... not sure. At minimum, we can work around the issue, and now I know what to look for in future.

[odow]

I can load Gurobi 10 without any issues (this version doesn't have the --remove-signature in it), so maybe something has changed on your end:

(grb) pkg> add Gurobi_jll@10
   Resolving package versions...
   Installed Gurobi_jll ─ v10.0.3
     Failure artifact: Gurobi
  Downloaded artifact: Gurobi
    Updating `/private/tmp/grb/Project.toml`
⌃ [c018c7e6] ↓ Gurobi_jll v11.0.1 ⇒ v10.0.3
    Updating `/private/tmp/grb/Manifest.toml`
⌃ [c018c7e6] ↓ Gurobi_jll v11.0.1 ⇒ v10.0.3
        Info Packages marked with ⌃ have new versions available and may be upgradable.
Precompiling project...
  1 dependency successfully precompiled in 2 seconds. 2 already precompiled.

julia> using Gurobi_jll

julia> Gurobi_jll.libgurobi
"/Users/oscar/.julia/artifacts/9747c6ef8280f98316f91aea9accc9e5808d92ed/lib/libgurobi100.dylib"

julia> run(`codesign -dvv $(Gurobi_jll.libgurobi)`)
/Users/oscar/.julia/artifacts/9747c6ef8280f98316f91aea9accc9e5808d92ed/lib/libgurobi100.dylib: code object is not signed at all