Fix parsing of docker options.

Fix parsing `DOCKER_OPTS` to correctly parse them as shell words, rather
than splitting on whitespace.

Closes #769.

CHANGELOG.md

@@ -7,6 +7,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+- #771 - fix parsing of `DOCKER_OPTS`.
 - #767 - added the `cross-util` and `cross-dev` commands.
 - #745 - added `thumbv7neon-*` targets.
 - #741 - added `armv7-unknown-linux-gnueabi` and `armv7-unknown-linux-musleabi` targets.

Cargo.toml

@@ -27,6 +27,7 @@ serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 serde_yaml = { version = "0.8", optional = true }
 serde_ignored = "0.1.2"
+shell-words = "1.1.0"
 
 [target.'cfg(not(windows))'.dependencies]
 nix = { version = "0.24", default-features = false, features = ["user"] }

src/docker.rs

@@ -312,7 +312,8 @@ pub fn run(
     }
 
     if let Ok(value) = env::var("DOCKER_OPTS") {
-        let opts: Vec<&str> = value.split(' ').collect();
+        let opts = shell_words::split(&value)
+            .wrap_err_with(|| format!("could not pass docker opts of {}", value))?;
         docker.args(&opts);
     }