Fixes to previously-failing tests

Author: arxanas

nextest-runner/src/list/test_list.rs

@@ -24,7 +24,7 @@ use nextest_metadata::{
 use once_cell::sync::{Lazy, OnceCell};
 use owo_colors::OwoColorize;
 use std::{
-    collections::{BTreeMap, BTreeSet, HashMap, HashSet},
+    collections::{BTreeMap, BTreeSet, HashMap},
     ffi::{OsStr, OsString},
     io,
     io::Write,
@@ -908,10 +908,13 @@ pub(crate) fn make_test_command(
     };
 
     // NB: we will always override user-provided environment variables with the
-    // ones we set below.
-    let mut existing_keys: HashSet<_> = std::env::vars_os()
-        .map(|(k, _v)| k)
-        .map(make_windows_compatible_key)
+    // `CARGO_*` and `NEXTEST_*` variables set directly on `cmd` below.
+    enum EnvSource {
+        Env,
+        CargoConfig,
+    }
+    let mut existing_keys: HashMap<OsString, EnvSource> = std::env::vars_os()
+        .map(|(k, _v)| (make_windows_compatible_key(k), EnvSource::Env))
         .collect();
     for CargoEnvironmentVariable {
         source,
@@ -922,7 +925,20 @@ pub(crate) fn make_test_command(
     } in env
     {
         let name_os_string = make_windows_compatible_key(OsString::from(name));
-        if !existing_keys.insert(name_os_string) && !force {
+        let should_set_value = match existing_keys.insert(name_os_string, EnvSource::CargoConfig) {
+            None => {
+                // No key with this name was set, proceed to set the value.
+                true
+            }
+            Some(EnvSource::CargoConfig) => {
+                // Always prefer previously-set cargo config values, since they have higher
+                // precedence. Note that `force` only applies to overwriting environment variables,
+                // not other cargo config values.
+                false
+            }
+            Some(EnvSource::Env) => *force,
+        };
+        if !should_set_value {
             continue;
         }