Cover multiple cases

docs/setup.en.md

@@ -48,11 +48,18 @@ You need to generate config file via `npm run config` command.
 *5.* Build Misskey
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+Build misskey with the following:
+
+`npm run build`
+
 If you're on Debian, you will need to install the `build-essential` package.
 
-Then build misskey:
+If you're still encountering errors about some modules, use node-gyp:
 
-`npm run build`
+1. `npm install -g node-gyp`
+2. `node-gyp configure`
+3. `node-gyp build`
+4. `npm run build`
 
 *6.* That is it.
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