Regression of rustup doc BROWSER environment variable support in #1287

[jer-irl]

Problem

Bug #1287 and PR #1289 added support for the BROWSER environment variable to allow overrides to the XDG default browser when running rustup doc.

Steps

1. BROWSER=$(some-non-default) rustup doc
2. Documentation opened in XDG default browser

Possible Solution(s)

It looks to me like this feature was reverted with the move to opener in this commit e661fc6

It looks like cargo still handles this environment variable and just falls back to opener https://github.com/rust-lang/cargo/blob/master/src/cargo/ops/cargo_doc.rs#L101 . Would PRs to restore this feature be welcome? I'd imagine it would be pretty small and self-contained.

Notes

Output of rustup --version: cargo 1.49.0 (d00d64df9 2020-12-05)
Output of rustup show:

Default host: x86_64-unknown-linux-gnu
rustup home:  /home/jeremy/.rustup

stable-x86_64-unknown-linux-gnu (default)
rustc 1.49.0 (e1884a8e3 2020-12-29)

[kinnison]

While I concur that this is a regression, I wonder if the right answer is to push the handling of BROWSER into the opener crate, rather than duplicating logic between here and Cargo.

@Seeker14491 how would you feel about BROWSER environment variable handling being pushed into opener as per the linked approach in Cargo?

[Seeker14491]

Having the BROWSER override implemented in opener is planned for the next release and is already implemented in the v0.5-dev branch.

[kinnison]

@Seeker14491 That's fantastic news. Do you have a timeline on releasing that?

[kinnison]

@Seeker14491 I appreciate we're pinging you quite a bit recently, but... any word on 0.5 ?

[Seeker14491]

I'm having another go at fixing several issues people have reported in the opener crate, and I plan on putting out a release within a few days at most.

[kinnison]

I'm having another go at fixing several issues people have reported in the opener crate, and I plan on putting out a release within a few days at most.

That is fantastic news. Please don't let me rush you though - take your time :D

[Seeker14491]

This should be fixed now with the merging of #2792.

[kinnison]

Aha thanks @Seeker14491

[sudoforge]

Is there any chance that this could be added to a 1.24.4 release?

[sudoforge]

What I'm really asking/saying is:

I'm impatient and would like this to be considered a hotfix, considering it is a regression.

For additonal context, it doesn't appear to use either the BROWSER environment variable, or the default browser set with XDG. I'm going to open an issue with opener directly.

➜ echo $BROWSER
qutebrowser
                                                                                                                        

➜ xdg-settings get default-web-browser
org.qutebrowser.qutebrowser.desktop


➜ pstree 918976
rustup───sh───chromium─┬─chromium───chromium───19*[{chromium}]
                       ├─chromium───chromium─┬─chromium───5*[{chromium}]
                       │                     └─2*[chromium───12*[{chromium}]]
                       ├─chromium───7*[{chromium}]
                       └─19*[{chromium}]

[sudoforge]

To any future readers, this was due to the xdg-mime configuration for text/html being set to chromium.desktop. To resolve this:

xdg-mime default <your preferred application> text/html