Add some output

src/index.ts

@@ -104,13 +104,16 @@ async function rebuild() {
     'sourcemap.json',
     JSON.stringify(sourcemap, null, 2),
   )
+  console.log('Sourcemap rebuilt.')
 }
 
 for (const root of SOURCE_ROOTS) {
   fs.watch(root, { recursive: true }, () => {
+    console.log(`Detected change in ${root}, rebuilding sourcemap...`)
     sourcemapCache.delete(root)
     rebuild()
   })
 }
 
+console.log('Rebuilding sourcemap...')
 rebuild()