desktop: log which webview library actually loaded

cmd/desktop/boot_env_linux.go

@@ -18,6 +18,11 @@ import (
 // are also served in the diagnostics snapshot — see internal/desktopenv.
 func logBootEnv() {
 	log.Printf("[desktop] session: %s", joinEnv(desktopenv.SessionKeys, true))
+	// The webview build decides which rendering bugs apply, and the package
+	// manager's answer is not necessarily the library that got loaded.
+	if lib := desktopenv.WebviewLibrary(); lib != "" {
+		log.Printf("[desktop] webview: %s", lib)
+	}
 	if s := joinEnv(desktopenv.OverrideKeys, false); s != "" {
 		log.Printf("[desktop] render overrides: %s", s)
 	}

internal/desktopenv/desktopenv.go

@@ -62,3 +62,8 @@ func GPUPolicy() string {
 // Collect returns the current environment, or nil on platforms where none of
 // this applies.
 func Collect() *Snapshot { return collect() }
+
+// WebviewLibrary returns the webview library mapped into this process, or ""
+// where that cannot be determined. Exposed separately from Collect so startup
+// logging can name the build before anything else has run.
+func WebviewLibrary() string { return webviewLibrary() }

internal/desktopenv/desktopenv_linux.go

@@ -16,7 +16,7 @@ func collect() *Snapshot {
 		DisplayServer:      displayServer(),
 		RenderOverrides:    readAll(OverrideKeys),
 		Sandbox:            readSet(SandboxKeys),
-		WebKitLibrary:      webKitLibrary("/proc/self/maps"),
+		WebKitLibrary:      webviewLibrary(),
 		GPUPolicy:          GPUPolicy(),
 	}
 	return s
@@ -56,6 +56,8 @@ func readSet(keys []string) []EnvVar {
 	return out
 }
 
+func webviewLibrary() string { return webKitLibrary("/proc/self/maps") }
+
 // webKitLibrary returns the basename of the webview library mapped into this
 // process. The soname's trailing version identifies the WebKitGTK build, which
 // a bug report otherwise has no way to state. The prefix is matched loosely

internal/desktopenv/desktopenv_other.go

@@ -5,3 +5,5 @@ package desktopenv
 // collect reports nothing off Linux. macOS (WKWebView) and Windows (WebView2)
 // have no equivalent set of host render knobs to surface.
 func collect() *Snapshot { return nil }
+
+func webviewLibrary() string { return "" }