Symlinked home directory causes persistent "not compatible with prefix option" error

[mvastola]

Operating system and version:

Ubuntu 19.10

nvm debug output:

nvm --version: v0.35.3
$SHELL: /bin/bash
$SHLVL: 1
${HOME}: /home/mvastola
${NVM_DIR}: '${HOME}/.nvm'
${PATH}: /usr/local/rvm/gems/ruby-2.7.0/bin:/usr/local/rvm/gems/ruby-2.7.0@global/bin:/usr/local/rvm/rubies/ruby-2.7.0/bin:/usr/local/rvm/bin:${HOME}/.local/bin:${HOME}/bin:${HOME}/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/usr/brlcad/bin:${HOME}/.dotnet/tools:/usr/lib/jvm/default-java/bin:/usr/lib/jvm/default-java/db/bin:/usr/lib/jvm/default-java/jre/bin
$PREFIX: ''
${NPM_CONFIG_PREFIX}: ''
$NVM_NODEJS_ORG_MIRROR: ''
$NVM_IOJS_ORG_MIRROR: ''
shell version: 'GNU bash, version 5.0.3(1)-release (x86_64-pc-linux-gnu)'
uname -a: 'Linux 5.3.0-59-generic #53-Ubuntu SMP Wed Jun 3 15:52:15 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux'
OS version: Ubuntu 19.10
curl: /usr/bin/curl, curl 7.65.3 (x86_64-pc-linux-gnu) libcurl/7.65.3 OpenSSL/1.1.1c zlib/1.2.11 libidn2/2.2.0 libpsl/0.20.2 (+libidn2/2.0.5) libssh/0.9.0/openssl/zlib nghttp2/1.39.2 librtmp/2.3
wget: /usr/bin/wget, GNU Wget 1.20.3 built on linux-gnu.
git: /usr/bin/git, git version 2.20.1
grep: /bin/grep (grep --color=auto), grep (GNU grep) 3.3
awk: /usr/bin/awk, GNU Awk 4.2.1, API: 2.0 (GNU MPFR 4.0.2, GNU MP 6.1.2)
sed: /bin/sed, sed (GNU sed) 4.7
cut: /usr/bin/cut, cut (GNU coreutils) 8.30
basename: /usr/bin/basename, basename (GNU coreutils) 8.30
rm: /bin/rm, rm (GNU coreutils) 8.30
mkdir: /bin/mkdir, mkdir (GNU coreutils) 8.30
xargs: /usr/bin/xargs, xargs (GNU findutils) 4.6.0.225-235f
nvm current: none
which node:
which iojs:
which npm:
npm config get prefix:
Command 'npm' not found, but can be installed with:

sudo apt install npm
npm root -g:
Command 'npm' not found, but can be installed with:

sudo apt install npm

Background

On my system, I have my /home folder symlinked to /media/SOME_NAME/home, as my home directories reside on a different partition. I never updated my users' home directories in /etc/passwd because it never seemed necessary (that is, /etc/passwd still contains home directories such as /home/mvastola).

The Issue

Whenever I run nvm use default, however, I get the following error message:

nvm is not compatible with the npm config "prefix" option: currently set to "/media/SOME_NAME/home/mvastola/.nvm/versions/node/v14.4.0"
Run `nvm use --delete-prefix v14.4.0 --silent` to unset it.

The Cause

It appears that this error is occurring due to this line of code in nvm.sh.

Specifically, the command in that line evaluates to: nvm_tree_contains_path /home/mvastola/.nvm /media/SOME_NAME/home/mvastola/.nvm/versions/node/v14.4.0. This function has a non-zero return value, and the error above is generated.

Obviously, the underlying issue is either:
a) that the first path listed (the NVM_DIR environment var set in .bashrc) should be absolute, or;
b) that the second path listed (obtained from running npm config --loglevel=warn get prefix) shouldn't be absolute.

Clearly, (a) is due to the export NVM_DIR="$HOME/.nvm" inserted into .bashrc at install time.

I'm not entirely sure where the second path comes from, but my best guess is that it came from $HOME/.nvm/versions/node/v14.4.0/lib/node_modules/npm/package.json, where _where key contains the absolute path to my home directory.

The Workaround

I was able to patch this issue by simply replacing export NVM_DIR="$HOME/.nvm" in .bashrc to contain the absolute path of home.

The Fix

I'm not sure where the _where key in $HOME/.nvm/versions/node/v14.4.0/lib/node_modules/npm/package.json was set, but if it was set by npm itself, stoping npm from resolving symlinks (or otherwise un-resolving them doesn't seem like a practical solution).

Instead, I would suggest updating the line in .bashrc to be:

export NVM_DIR="$(readlink -e "$HOME")/.nvm"

Please let me know if there's any additional info I can provide or if you have other questions or want me to test alternate solutions.

Note that, per advice in other GitHub issues, I have ensured there are no other instances of npm in any of my PATH directories, and there are no extraneous npmrc files in my filesystem. I have also deleted all non-nvm node_modules folders.

[ljharb]

nvm does not currently support $HOME or $NVM_DIR being a symlink; duplicate of #617.

[mvastola]

Oh. Thanks. I tried searching but that must have been buried in all the other issues from people getting the prefix error and it being because of .nvmrc or old node installs.