From 896257a1bdb9a4b29bc19d07c0819e6f3f98a3d5 Mon Sep 17 00:00:00 2001
From: Ignas Anikevicius <240938+aignas@users.noreply.github.com>
Date: Fri, 22 Sep 2023 12:30:27 +0900
Subject: [PATCH 1/2] fix(gazelle): fix runfiles discovery

---
 CHANGELOG.md                  |  2 ++
 gazelle/python/parser.go      |  9 ++++++++-
 gazelle/python/std_modules.go | 11 +++++++++--
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e319d28fb5..17d284ab92 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -58,6 +58,8 @@ A brief description of the categories of changes:
   dependencies improving initial build times involving external dependency
   fetching.
 
+* (gazelle) Improve runfiles lookup hermeticity.
+
 ## [0.25.0] - 2023-08-22
 
 ### Changed
diff --git a/gazelle/python/parser.go b/gazelle/python/parser.go
index c45aef139a..2dfcfa35e1 100644
--- a/gazelle/python/parser.go
+++ b/gazelle/python/parser.go
@@ -38,13 +38,20 @@ var (
 )
 
 func startParserProcess(ctx context.Context) {
-	parseScriptRunfile, err := runfiles.Rlocation("rules_python_gazelle_plugin/python/parse")
+	rfiles, err := runfiles.New()
+	if err != nil {
+		log.Printf("failed to create a runfiles object: %v\n", err)
+		os.Exit(1)
+	}
+
+	parseScriptRunfile, err := rfiles.Rlocation("rules_python_gazelle_plugin/python/parse")
 	if err != nil {
 		log.Printf("failed to initialize parser: %v\n", err)
 		os.Exit(1)
 	}
 
 	cmd := exec.CommandContext(ctx, parseScriptRunfile)
+	cmd.Env = rfiles.Env()
 
 	cmd.Stderr = os.Stderr
 
diff --git a/gazelle/python/std_modules.go b/gazelle/python/std_modules.go
index 15ef766ff2..a87deec366 100644
--- a/gazelle/python/std_modules.go
+++ b/gazelle/python/std_modules.go
@@ -39,7 +39,13 @@ var (
 func startStdModuleProcess(ctx context.Context) {
 	stdModulesSeen = make(map[string]struct{})
 
-	stdModulesScriptRunfile, err := runfiles.Rlocation("rules_python_gazelle_plugin/python/std_modules")
+	rfiles, err := runfiles.New()
+	if err != nil {
+		log.Printf("failed to create a runfiles object: %v\n", err)
+		os.Exit(1)
+	}
+
+	stdModulesScriptRunfile, err := rfiles.Rlocation("rules_python_gazelle_plugin/python/std_modules")
 	if err != nil {
 		log.Printf("failed to initialize std_modules: %v\n", err)
 		os.Exit(1)
@@ -49,7 +55,8 @@ func startStdModuleProcess(ctx context.Context) {
 
 	cmd.Stderr = os.Stderr
 	// All userland site-packages should be ignored.
-	cmd.Env = []string{"PYTHONNOUSERSITE=1"}
+	cmd.Env = append([]string{"PYTHONNOUSERSITE=1"}, rfiles.Env()...)
+
 	stdin, err := cmd.StdinPipe()
 	if err != nil {
 		log.Printf("failed to initialize std_modules: %v\n", err)

From b485d1bd79c8e4da086aa062042200f5f4fc75e8 Mon Sep 17 00:00:00 2001
From: Ignas Anikevicius <240938+aignas@users.noreply.github.com>
Date: Mon, 25 Sep 2023 11:13:46 +0900
Subject: [PATCH 2/2] comment: do not drop existing env vars in parser.go

---
 gazelle/python/parser.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gazelle/python/parser.go b/gazelle/python/parser.go
index 2dfcfa35e1..60a3c24269 100644
--- a/gazelle/python/parser.go
+++ b/gazelle/python/parser.go
@@ -51,7 +51,7 @@ func startParserProcess(ctx context.Context) {
 	}
 
 	cmd := exec.CommandContext(ctx, parseScriptRunfile)
-	cmd.Env = rfiles.Env()
+	cmd.Env = append(os.Environ(), rfiles.Env()...)
 
 	cmd.Stderr = os.Stderr