Misinterpretation of relative path to `--config`

[FlyingRatBull]

When calling cargo build-all-features --config .config/myconfig.toml, the build fails where it succeeds with just cargo build --config .config/myconfig.toml:

    Building crate=analyze_data features=[]
error: failed to parse value from --config argument `.cargo/myconfig.toml` as a dotted key expression

Caused by:
  TOML parse error at line 1, column 21
    |
  1 | .cargo/myconfig.toml
    |                     ^
  missing value for key, expected `=`