ARM version not detected for 32-bit arm versions

[paulober]

SerialPort Bindings Version

10.7.0

Node Version

16.15.0

Electron Version

19.0.12

Platform

Linux raspberrypi 5.15.61-v7l+ #1579 SMP Fri Aug 26 11:13:03 BST 2022 armv7l GNU/Linux

Architecture

ARM

Hardware or chipset of serialport

Etc

What steps will reproduce the bug?

Run a VSCode extension with serialport on a raspberry pi with the 32-bit Raspberry Pi OS.

What happens?

At runtime node-gyp-build gets "default" as the value for "armv". But actually the armv on a 32-bit Raspberry Pi 4b is 7. So the result is that it compares 6 and 7 (the two prebuild arm version) agains "default" which will of course fail! The reason for that is following line https://github.com/prebuild/node-gyp-build/blob/0078d7884dfeb0e708477b3e20bfc4f520c1e2f8/index.js#L16

var vars = (process.config && process.config.variables) || {}
.
.
.
var armv = process.env.ARM_VERSION || (arch === 'arm64' ? '8' : vars.arm_version) || ''

What should have happened?

That the arm version is correctly detected so it can detect which prebuild is the right.

Additional information

You either have to set process.env.ARM_VERSION or ensure that process.config.variables.arm_version get overwritten to "default".

[paulober]

I think that serialport or one of its dependency does somewhere overwrite the process.config.variables.arm_version with "default" as the normal nodejs install on this system shows "7" for process.config.variables which is correct. Or maybe VSCode or electron does overwrite it.

[paulober]

My current patch is to replace the var armv line in node-gyp-build with following:

// ARMv7 detection patched to avoid arm_version === "default" on other arm systems than arm64 ones
var armv = process.env.ARM_VERSION || (arch === 'arm64' ? '8' : (arch === 'arm' ? (vars.arm_version === 'default' ? '7' : vars.arm_version) : '')) || ''

This defaults to armv7 for arm systems where the arm_version has been overwritten to "default".

Note that's not a node-gyp-build bug as it functions perfectly well if the global process.config.variables.arm_version variable would not be overwritten with "default".

[reconbot]

It's not something serialport does directly.