Try #661:

CHANGELOG.md

@@ -5,6 +5,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+- #661 - Panic when image does not exist and running on CI or with `CROSS_FORCE_IMAGE=1`
 - #658 - Upgrade dependencies
 - #647 - Add `mips64-unknown-linux-muslabi64` and `mips64el-unknown-linux-muslabi64` support
 - #652 - Allow trying individual targets via bors.

Cargo.toml

@@ -14,6 +14,7 @@ edition = "2018"
 atty = "0.2"
 error-chain = "0.12"
 home = "0.5"
+is_ci = "1"
 lazy_static = "1.0"
 libc = "0.2.104"
 rustc_version = "0.4"

src/cli.rs

@@ -13,6 +13,7 @@ pub struct Args {
     pub target: Option<Target>,
     pub target_dir: Option<PathBuf>,
     pub docker_in_docker: bool,
+    pub force_image: bool,
 }
 
 pub fn parse(target_list: &TargetList) -> Args {
@@ -65,6 +66,9 @@ pub fn parse(target_list: &TargetList) -> Args {
     let docker_in_docker = env::var("CROSS_DOCKER_IN_DOCKER")
         .map(|s| bool::from_str(&s).unwrap_or_default())
         .unwrap_or_default();
+    let force_image = env::var("CROSS_FORCE_IMAGE")
+        .map(|s| bool::from_str(&s).unwrap_or_default())
+        .unwrap_or_default();
 
     Args {
         all,
@@ -73,5 +77,6 @@ pub fn parse(target_list: &TargetList) -> Args {
         target,
         target_dir,
         docker_in_docker,
+        force_image,
     }
 }

src/main.rs

@@ -343,6 +343,9 @@ fn run() -> Result<ExitStatus> {
 
             let image_exists = match docker::image(&config, &target) {
                 Ok(_) => true,
+                Err(err) if is_ci::uncached() || args.force_image => {
+                    return Err(err).map_err(Into::into)
+                }
                 Err(err) => {
                     eprintln!("Warning: {} Falling back to `cargo` on the host.", err);
                     false