Add more error message for conda create env

tests/common/mod.rs

@@ -1,4 +1,4 @@
-use anyhow::{bail, Result};
+use anyhow::{bail, Context, Result};
 use fs_err as fs;
 use maturin::Target;
 use normpath::PathExt as _;
@@ -85,6 +85,7 @@ pub fn maybe_mock_cargo() {
 }
 
 /// Better error formatting
+#[track_caller]
 pub fn handle_result<T>(result: Result<T>) -> T {
     match result {
         Err(e) => {
@@ -199,7 +200,21 @@ pub fn create_conda_env(name: &str, major: usize, minor: usize) -> Result<(PathB
         .arg("--json")
         .output()
         .expect("Conda not available.");
-    let result: CondaCreateResult = serde_json::from_slice(&output.stdout)?;
+    if !output.status.success() {
+        panic!(
+            "Failed to create conda environment: {}\n---stdout:\n{}---stderr:\n{}",
+            output.status,
+            str::from_utf8(&output.stdout)?,
+            str::from_utf8(&output.stderr)?
+        );
+    }
+    let result: CondaCreateResult = serde_json::from_slice(&output.stdout).with_context(|| {
+        format!(
+            "Failed to deserialize conda create command output:\n---stdout:\n{}---stderr:\n{}",
+            str::from_utf8(&output.stdout).unwrap(),
+            str::from_utf8(&output.stderr).unwrap(),
+        )
+    })?;
     if !result.success {
         bail!("Failed to create conda environment {}.", name);
     }