Multiple errors while installing nodejs serialport module - node.js

Question

I'm running raspbian on my raspberry pi 3. I'm trying to install the serialport module and many errors show up.
pi#raspberrypi:~/pmsensor $ sudo npm install --save serialport --fix-missing
This is what i get:
serialport#4.0.7 install /home/pi/pmsensor/node_modules/serialport
node-pre-gyp install --fallback-to-build
node-pre-gyp ERR! Tried to download(404): https://github.com/EmergingTechnologyAdvisors/node-serialport/releases/download/4.0.7/serialport-v4.0.7-node-v48-linux-arm.tar.gz
node-pre-gyp ERR! Pre-built binaries not found for serialport#4.0.7 and node#6.9.5 (node-v48 ABI) (falling back to source compile with node-gyp)
gyp WARN EACCES user "root" does not have permission to access the dev dir "/root/.node-gyp/6.9.5"
gyp WARN EACCES attempting to reinstall using temporary dev dir "/home/pi/pmsensor/node_modules/serialport/.node-gyp"
make: Entering directory '/home/pi/pmsensor/node_modules/serialport/build'
make: *** No rule to make target '../.node-gyp/6.9.5/include/node/common.gypi', needed by 'Makefile'. Stop.
make: Leaving directory '/home/pi/pmsensor/node_modules/serialport/build'
gyp ERR! build error
gyp ERR! stack Error: `make` failed with exit code: 2
gyp ERR! stack at ChildProcess.onExit (/usr/lib/node_modules/npm/node_modules/node-gyp/lib/build.js:276:23)
gyp ERR! stack at emitTwo (events.js:106:13)
gyp ERR! stack at ChildProcess.emit (events.js:191:7)
gyp ERR! stack at Process.ChildProcess._handle.onexit (internal/child_process.js:215:12)
gyp ERR! System Linux 4.4.48-v7+
gyp ERR! command "/usr/bin/nodejs" "/usr/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "build" "--fallback-to-build" "--module=/home/pi/pmsensor/node_modules/serialport/build/Release/serialport.node" "--module_name=serialport" "--module_path=/home/pi/pmsensor/node_modules/serialport/build/Release"
gyp ERR! cwd /home/pi/pmsensor/node_modules/serialport
gyp ERR! node -v v6.9.5
gyp ERR! node-gyp -v v3.4.0
gyp ERR! not ok
node-pre-gyp ERR! build error
node-pre-gyp ERR! stack Error: Failed to execute '/usr/bin/nodejs /usr/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js build --fallback-to-build --module=/home/pi/pmsensor/node_modules/serialport/build/Release/serialport.node --module_name=serialport --module_path=/home/pi/pmsensor/node_modules/serialport/build/Release' (1)
node-pre-gyp ERR! stack at ChildProcess.<anonymous> (/home/pi/pmsensor/node_modules/serialport/node_modules/node-pre-gyp/lib/util/compile.js:83:29)
node-pre-gyp ERR! stack at emitTwo (events.js:106:13)
node-pre-gyp ERR! stack at ChildProcess.emit (events.js:191:7)
node-pre-gyp ERR! stack at maybeClose (internal/child_process.js:877:16)
node-pre-gyp ERR! stack at Process.ChildProcess._handle.onexit (internal/child_process.js:226:5)
node-pre-gyp ERR! System Linux 4.4.48-v7+
node-pre-gyp ERR! command "/usr/bin/nodejs" "/home/pi/pmsensor/node_modules/serialport/node_modules/.bin/node-pre-gyp" "install" "--fallback-to-build"
node-pre-gyp ERR! cwd /home/pi/pmsensor/node_modules/serialport
node-pre-gyp ERR! node -v v6.9.5
node-pre-gyp ERR! node-pre-gyp -v v0.6.32
node-pre-gyp ERR! not ok
Failed to execute '/usr/bin/nodejs /usr/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js build --fallback-to-build --module=/home/pi/pmsensor/node_modules/serialport/build/Release/serialport.node --module_name=serialport --module_path=/home/pi/pmsensor/node_modules/serialport/build/Release' (1)
npm WARN pmsensor#1.0.0 No repository field.
npm ERR! Linux 4.4.48-v7+
npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "install" "--save" "serialport" "--fix-missing"
npm ERR! node v6.9.5
npm ERR! npm v3.10.10
npm ERR! code ELIFECYCLE
npm ERR! serialport#4.0.7 install: `node-pre-gyp install --fallback-to-build`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the serialport#4.0.7 install script 'node-pre-gyp install --fallback-to-build'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the serialport package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! node-pre-gyp install --fallback-to-build
npm ERR! You can get information on how to open an issue for this project with:
npm ERR! npm bugs serialport
npm ERR! Or if that isn't available, you can get their info via:
npm ERR! npm owner ls serialport
npm ERR! There is likely additional logging output above.
npm ERR! Please include the following file with any support request:
npm ERR! /home/pi/pmsensor/npm-debug.log

Answer 1

You correctly figured out how to solve this. With the raspberry pi people usually run as root (as you are) and if you want to install a binary package with root (maybe any package), you need to use the --unsafe-perm flag with npm. The node serialport docs have more information.
https://github.com/EmergingTechnologyAdvisors/node-serialport#sudo--root