Allow rustdoc to get compiled with debuginfo

[Mark-Simulacrum]

Fixes #44810

cc @QuietMisdreavus
r? @alexcrichton

[kennytm]

Should be build.config, not self.config.

[00:02:02] error[E0609]: no field `config` on type `tool::Rustdoc`
[00:02:02]    --> /checkout/src/bootstrap/tool.rs:309:43
[00:02:02]     |
[00:02:02] 309 |         cargo.env("RUSTC_DEBUGINFO", self.config.rust_debuginfo.to_string())
[00:02:02]     |                                           ^^^^^^ unknown field
[00:02:02]     |
[00:02:02]     = note: available fields are: `host`
[00:02:02] 
[00:02:02] error[E0609]: no field `config` on type `tool::Rustdoc`
[00:02:02]    --> /checkout/src/bootstrap/tool.rs:310:49
[00:02:02]     |
[00:02:02] 310 |              .env("RUSTC_DEBUGINFO_LINES", self.config.rust_debuginfo_lines.to_string())
[00:02:02]     |                                                 ^^^^^^ unknown field
[00:02:02]     |
[00:02:02]     = note: available fields are: `host`
[00:02:02] 
[00:02:02] error: aborting due to 2 previous errors
[00:02:02] 
[00:02:02] error: Could not compile `bootstrap`.

[QuietMisdreavus]

librustdoc failed to build, citing the metadata flag:

[00:34:22] error[E0523]: found two different crates with name `env_logger` that are not distinguished by differing `-C metadata`. This will result in symbol conflicts between the two.
[00:34:22]   --> /checkout/src/librustdoc/lib.rs:37:1
[00:34:22]    |
[00:34:22] 37 | extern crate rustc_driver;
[00:34:22]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[00:34:22] 
[00:34:22] error: Could not compile `rustdoc`.

[QuietMisdreavus]

I checked out this branch, and can confirm that Visual Studio happily set breakpoints and stepped through code in librustdoc with this change.

[alexcrichton]

I don't think this env var is necessary because we're not shipping rlibs, just the rustdoc executable

[alexcrichton]

r=me with one minor nit

[Mark-Simulacrum]

@bors r+

[bors]

📌 Commit 33b5ec3 has been approved by Mark-Simulacrum

[Mark-Simulacrum]

@bors r=alexcrichton p=1

Nominating for beta backport. Tiny patch, and I think without this we may lose nice ICEs from rustdoc. Not overly concerned, though, and I'm not sure how much debug information we ship anyway...

[bors]

💡 This pull request was already approved, no need to approve it again.

• There's another pull request that is currently being tested, blocking this pull request: macros: fix bug in collecting trait and impl items with derives. #44757

[bors]

📌 Commit 33b5ec3 has been approved by alexcrichton

[alexcrichton]

I don't think we've had rustdoc debuginfo turned on for quite awhile now, right?

[alexcrichton]

(in that I wouldn't personally be inclined to backport)

[bors]

⌛ Testing commit 33b5ec3 with merge e53ab91...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: alexcrichton
Pushing e53ab91 to master...

[Mark-Simulacrum]

Yeah, I don't really care about the backport. I'll denominate -- we can always backport if necessary.