Incorrect RUSTFLAGS parsing (part deux)

[lrascao]

Problem/Steps

% cargo new aa
% cd aa
$ RUSTFLAGS="--codegen link-args='-flat_namespace -undefined suppress'" cargo build

error: failed to run `rustc` to learn about target-specific information

Caused by:
  process didn't exit successfully: `rustc - --crate-name ___ --print=file-names --codegen 'link-args='\''-flat_namespace' -undefined 'suppress'\''' --crate-type bin --crate-type rlib --crate-type dylib --
crate-type cdylib --crate-type staticlib --crate-type proc-macro --print=sysroot --print=cfg` (exit code: 1)
--- stderr
error: Unrecognized option: 'u'

(Ugly) Alternative that does work:

RUSTFLAGS="--codegen link-arg=-flat_namespace --codegen link-arg=-undefined --codegen link-arg=suppress" cargo build
   Compiling aa v0.1.0 (/private/tmp/aa)
    Finished dev [unoptimized + debuginfo] target(s) in 1.29s

Notes

$ cargo --version
cargo 1.41.0 (626f0f4 2019-12-03)

[lrascao]

Previous discussion of same issue here

[ehuss]

Hi, thanks for the report! I'm going to close this as a duplicate of #6139, #3686, and #7406. See #7406 for a nightly-only option which allows TOML syntax in environment variables.

[lrascao]

👍