A batch of updates to get to xgboost 2.0.3

[montanalow]

• builds with xgboost v2.0.3
• expose cuda support as a feature
• some additional OS X (openmp) compatibility for homebrew
• move upstream to dmlc/xgboost
• fix cargo dependencies for git submodules
• update cargo dependencies
• update DMatrix uri loading format for 2.0 compat
• fix cargo clippy lints
  • static lifetimes are no longer required
• fix dmatrix slicing out of bounds segfault
• cargo fmt (rustfmt.toml to minimize changes where possible)

Needs detailed review:

• From csr does not pass tests, but from csc is easier for me to reason about:
  • master...postgresml:rust-xgboost:master#diff-5395154ef0eed4cb8417ab3dfac078a8e79d26947d6967aa0800ad0460d81b1aR67

[davechallis]

@montanalow Thanks for this, looks good on quick read through! I'll spend a bit of time reviewing in detail shortly (just dealing with a bit of a backlog after xmas...).

[davechallis]

Code changes mostly look good I think.

I'm having some trouble building xgboost-sys after the changes though, so still investigating that. I get the errors:

error[E0412]: cannot find type `_Tp` in this scope
   --> /Users/dsc/src/rust-xgboost/xgboost-sys/target/debug/build/xgboost-sys-95c0101c1ac52cb0/out/bindings.rs:452:27
    |
452 |     pub static std_value: _Tp;
    |                           ^^^ not found in this scope

For more information about this error, try `rustc --explain E0412`.
error: could not compile `xgboost-sys` (lib) due to previous error

I'll carry on trying to find the cause though, possible I'm using an outdated llvm install.

[davechallis]

iirc, this was originally pointed at a fork to deal with some build issues with the original library involving unused packages. Hopefully it's fixed now though (I'm hazy on the details, but was something to do with the python bindings perhaps...).

[davechallis]

It would be good to leave this as configurable (to allow for non-homebrew LLVM installs), and to allow for homebrew installs to different locations.

Homebrew defaults to /usr/local for intel macs, and /opt/homebrew for silicon: https://docs.brew.sh/FAQ#why-should-i-install-homebrew-in-the-default-location, so bound to be some variation here.

I had to comment out the above to compile, since I'm on an intel mac (hoping for an m1 someday...).

[montanalow]

I added a check for the m1 directory existence before adding these extras in 1da1c03

Let me know if this is still causing an issue for intel. I don't have a laptop I can test this one on.

[montanalow]

Code changes mostly look good I think.

I'm having some trouble building xgboost-sys after the changes though, so still investigating that. I get the errors:

error[E0412]: cannot find type `_Tp` in this scope
   --> /Users/dsc/src/rust-xgboost/xgboost-sys/target/debug/build/xgboost-sys-95c0101c1ac52cb0/out/bindings.rs:452:27
    |
452 |     pub static std_value: _Tp;
    |                           ^^^ not found in this scope

For more information about this error, try `rustc --explain E0412`.
error: could not compile `xgboost-sys` (lib) due to previous error

I'll carry on trying to find the cause though, possible I'm using an outdated llvm install.

This one took me a bit, but I think it's fixed by 0307a92