From 647b509c74583100dcc428b93ae9e1fe51bdc633 Mon Sep 17 00:00:00 2001
From: Joe Rickerby <joerick@mac.com>
Date: Mon, 18 Sep 2023 17:06:09 +0100
Subject: [PATCH 1/2] Add test for environment and environment_pass references

---
 unit_test/options_test.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/unit_test/options_test.py b/unit_test/options_test.py
index 134db012e..009900df2 100644
--- a/unit_test/options_test.py
+++ b/unit_test/options_test.py
@@ -253,3 +253,22 @@ def test_container_engine_option(tmp_path: Path, toml_assignment, result_name, r
 
     assert parsed_container_engine.name == result_name
     assert parsed_container_engine.create_args == result_create_args
+
+
+def test_environment_pass_references():
+    options = Options(
+        platform="linux",
+        command_line_arguments=CommandLineArguments.defaults(),
+        env={
+            "CIBW_ENVIRONMENT_PASS_LINUX": "STARTER MAIN_COURSE",
+            "STARTER": "green eggs",
+            "MAIN_COURSE": "ham",
+            "CIBW_ENVIRONMENT": 'MEAL="$STARTER and $MAIN_COURSE"',
+        },
+    )
+    parsed_environment = options.build_options(identifier=None).environment
+    assert parsed_environment.as_dictionary(prev_environment={}) == {
+        "MEAL": "green eggs and ham",
+        "STARTER": "green eggs",
+        "MAIN_COURSE": "ham",
+    }

From 62a06d28b51365be808658b576c67129fa9505ea Mon Sep 17 00:00:00 2001
From: Joe Rickerby <joerick@mac.com>
Date: Mon, 18 Sep 2023 17:08:30 +0100
Subject: [PATCH 2/2] Change order of environment-pass, so environment can
 reference it

---
 cibuildwheel/environment.py | 8 ++++++--
 cibuildwheel/options.py     | 4 ++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/cibuildwheel/environment.py b/cibuildwheel/environment.py
index d7727ae48..e4018b915 100644
--- a/cibuildwheel/environment.py
+++ b/cibuildwheel/environment.py
@@ -124,8 +124,12 @@ def as_dictionary(
 
         return environment
 
-    def add(self, name: str, value: str) -> None:
-        self.assignments.append(EnvironmentAssignmentRaw(name=name, value=value))
+    def add(self, name: str, value: str, prepend: bool = False) -> None:
+        assignment = EnvironmentAssignmentRaw(name=name, value=value)
+        if prepend:
+            self.assignments.insert(0, assignment)
+        else:
+            self.assignments.append(assignment)
 
     def __repr__(self) -> str:
         return f"{self.__class__.__name__}({[repr(a) for a in self.assignments]!r})"
diff --git a/cibuildwheel/options.py b/cibuildwheel/options.py
index 581e576b8..899240526 100644
--- a/cibuildwheel/options.py
+++ b/cibuildwheel/options.py
@@ -530,9 +530,9 @@ def build_options(self, identifier: str | None) -> BuildOptions:
 
             # Pass through environment variables
             if self.platform == "linux":
-                for env_var_name in environment_pass:
+                for env_var_name in reversed(environment_pass):
                     with contextlib.suppress(KeyError):
-                        environment.add(env_var_name, self.env[env_var_name])
+                        environment.add(env_var_name, self.env[env_var_name], prepend=True)
 
             if dependency_versions == "pinned":
                 dependency_constraints: None | (