[Fix] recognize 32Bit docker container and use x86 arch

[ds82]

nvm tries to download & install 64Bit node Versions inside a 32Bit docker container on a 64Bit host

[ljharb]

I'm confused, if you're inside a 32 bit container then it should read as 32bit.

(note that node itself doesn't support 32bit builds on non-windows, since like node 10)

[ds82]

No, docker needs a 64Bit Host (and kernel) and the host kernel is used inside the container, even if that container is 32bit. A 64Bit kernel can run 32Bit code.

# on the host
 ❯❯❯ uname -m
x86_64

# switch to container
❯❯❯ docker run --rm -it titan-bullseye-386:latest /bin/bash
root@d149fca9a6c6:/# uname -m
x86_64
root@d149fca9a6c6:/# getconf LONG_BIT
32

There are still unofficial 32Bit builds:
https://unofficial-builds.nodejs.org/download/release/

And this URL can be used as MIRROR with nvm:
NVM_NODEJS_ORG_MIRROR=https://unofficial-builds.nodejs.org/download/release/

[ljharb]

ah, gotcha. (relates to #3041)

[ljharb]

While we don't support unofficial builds, this seems narrow enough to be not as risky.