From 9d4a78427803535df0b589e48107a9f3b7973f1d Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Thu, 16 Apr 2026 13:29:10 -0700
Subject: [PATCH 1/4] runtime: handle GODEBUG on wasip2

---
 GNUmakefile               |  2 +-
 src/runtime/env.go        |  2 +-
 src/runtime/env_wasip2.go | 18 ++++++++++++++++++
 src/syscall/env_wasip2.go |  2 ++
 4 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 src/runtime/env_wasip2.go

diff --git a/GNUmakefile b/GNUmakefile
index eadcf13d04..167e8b79a6 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -488,7 +488,7 @@ TEST_PACKAGES_HOST := $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_WINDOWS)
 TEST_IOFS := false
 endif
 
-TEST_SKIP_FLAG := -skip='TestExtraMethods|TestParseAndBytesRoundTrip/P256/Generic|TestParseQueryLimits|TestParseStrictIpv6|TestAsValidation'
+TEST_SKIP_FLAG := -skip='TestExtraMethods|TestParseAndBytesRoundTrip/P256/Generic|TestAsValidation'
 TEST_ADDITIONAL_FLAGS ?=
 
 # Test known-working standard library packages.
diff --git a/src/runtime/env.go b/src/runtime/env.go
index 676c634d99..899321c266 100644
--- a/src/runtime/env.go
+++ b/src/runtime/env.go
@@ -1,4 +1,4 @@
-//go:build linux || darwin || windows || wasip1
+//go:build (linux || darwin || windows || wasip1) && !wasip2
 
 package runtime
 
diff --git a/src/runtime/env_wasip2.go b/src/runtime/env_wasip2.go
new file mode 100644
index 0000000000..7beb8695c5
--- /dev/null
+++ b/src/runtime/env_wasip2.go
@@ -0,0 +1,18 @@
+//go:build wasip2
+
+package runtime
+
+// Notify the runtime when environment variables change.
+// On wasip2, the environment is managed in Go (no C setenv), but
+// internal/godebug still needs to be notified of GODEBUG changes.
+
+//go:linkname syscallSetenv syscall.runtimeSetenv
+func syscallSetenv(key, value string) {
+	if key == "GODEBUG" && godebugUpdate != nil {
+		godebugUpdate(key, value)
+	}
+}
+
+//go:linkname syscallUnsetenv syscall.runtimeUnsetenv
+func syscallUnsetenv(key string) {
+}
diff --git a/src/syscall/env_wasip2.go b/src/syscall/env_wasip2.go
index 8064d0d281..f9468936bb 100644
--- a/src/syscall/env_wasip2.go
+++ b/src/syscall/env_wasip2.go
@@ -43,11 +43,13 @@ func Setenv(key, val string) (err error) {
 		}
 	}
 	libc_envs[key] = val
+	runtimeSetenv(key, val)
 	return nil
 }
 
 func Unsetenv(key string) (err error) {
 	delete(libc_envs, key)
+	runtimeUnsetenv(key)
 	return nil
 }
 

From 2b9290b384bb1a629a99145fcb6168ffed9f7355 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Sat, 18 Apr 2026 12:13:40 -0700
Subject: [PATCH 2/4] Support env on more platforms to get GODEBUG working

---
 src/runtime/env_nonhosted.go     | 43 ++++++++++++++++++++++++++++++++
 src/syscall/env_nonhosted.go     | 32 +++++++++++++++++++-----
 src/syscall/syscall_nonhosted.go |  4 +++
 3 files changed, 73 insertions(+), 6 deletions(-)
 create mode 100644 src/runtime/env_nonhosted.go

diff --git a/src/runtime/env_nonhosted.go b/src/runtime/env_nonhosted.go
new file mode 100644
index 0000000000..e3bef9dbcc
--- /dev/null
+++ b/src/runtime/env_nonhosted.go
@@ -0,0 +1,43 @@
+//go:build baremetal || js || wasm_unknown
+
+package runtime
+
+//go:linkname syscallSetenv syscall.runtimeSetenv
+func syscallSetenv(key, value string) {
+	entry := key + "=" + value
+	for i, e := range env {
+		if envKey(e) == key {
+			env[i] = entry
+			if key == "GODEBUG" && godebugUpdate != nil {
+				godebugUpdate(key, value)
+			}
+			return
+		}
+	}
+	env = append(env, entry)
+	if key == "GODEBUG" && godebugUpdate != nil {
+		godebugUpdate(key, value)
+	}
+}
+
+//go:linkname syscallUnsetenv syscall.runtimeUnsetenv
+func syscallUnsetenv(key string) {
+	for i, e := range env {
+		if envKey(e) == key {
+			env = append(env[:i], env[i+1:]...)
+			if key == "GODEBUG" && godebugUpdate != nil {
+				godebugUpdate(key, "")
+			}
+			return
+		}
+	}
+}
+
+func envKey(entry string) string {
+	for i := 0; i < len(entry); i++ {
+		if entry[i] == '=' {
+			return entry[:i]
+		}
+	}
+	return entry
+}
diff --git a/src/syscall/env_nonhosted.go b/src/syscall/env_nonhosted.go
index 446ba55d2d..98f198743b 100644
--- a/src/syscall/env_nonhosted.go
+++ b/src/syscall/env_nonhosted.go
@@ -28,18 +28,38 @@ func Getenv(key string) (value string, found bool) {
 }
 
 func Setenv(key, val string) (err error) {
-	// stub for now
-	return ENOSYS
+	if len(key) == 0 {
+		return EINVAL
+	}
+	for i := 0; i < len(key); i++ {
+		if key[i] == '=' || key[i] == 0 {
+			return EINVAL
+		}
+	}
+	for i := 0; i < len(val); i++ {
+		if val[i] == 0 {
+			return EINVAL
+		}
+	}
+	runtimeSetenv(key, val)
+	return nil
 }
 
 func Unsetenv(key string) (err error) {
-	// stub for now
-	return ENOSYS
+	runtimeUnsetenv(key)
+	return nil
 }
 
 func Clearenv() (err error) {
-	// stub for now
-	return ENOSYS
+	for _, s := range Environ() {
+		for j := 0; j < len(s); j++ {
+			if s[j] == '=' {
+				Unsetenv(s[:j])
+				break
+			}
+		}
+	}
+	return nil
 }
 
 func runtime_envs() []string
diff --git a/src/syscall/syscall_nonhosted.go b/src/syscall/syscall_nonhosted.go
index a0965692f4..82633a99f4 100644
--- a/src/syscall/syscall_nonhosted.go
+++ b/src/syscall/syscall_nonhosted.go
@@ -176,3 +176,7 @@ type RawSockaddrInet4 struct {
 type RawSockaddrInet6 struct {
 	// stub
 }
+
+// These two functions are provided by the runtime.
+func runtimeSetenv(key, value string)
+func runtimeUnsetenv(key string)

From f8808dec5e6ca937107108968d88327a835a736c Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Sat, 18 Apr 2026 12:18:00 -0700
Subject: [PATCH 3/4] Forgot some code

---
 src/runtime/env_wasip2.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/runtime/env_wasip2.go b/src/runtime/env_wasip2.go
index 7beb8695c5..ffc18d9253 100644
--- a/src/runtime/env_wasip2.go
+++ b/src/runtime/env_wasip2.go
@@ -15,4 +15,7 @@ func syscallSetenv(key, value string) {
 
 //go:linkname syscallUnsetenv syscall.runtimeUnsetenv
 func syscallUnsetenv(key string) {
+	if key == "GODEBUG" && godebugUpdate != nil {
+		godebugUpdate(key, "")
+	}
 }

From b65b29b608a6af8423faa3189ef73df5c0672620 Mon Sep 17 00:00:00 2001
From: Jake Bailey <5341706+jakebailey@users.noreply.github.com>
Date: Sat, 18 Apr 2026 12:28:43 -0700
Subject: [PATCH 4/4] Exclude even more

---
 src/runtime/env.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/runtime/env.go b/src/runtime/env.go
index 899321c266..f20cc0851d 100644
--- a/src/runtime/env.go
+++ b/src/runtime/env.go
@@ -1,4 +1,4 @@
-//go:build (linux || darwin || windows || wasip1) && !wasip2
+//go:build (linux || darwin || windows || wasip1) && !wasip2 && !baremetal && !wasm_unknown
 
 package runtime