ALIAS: unbound variable

[alexjurkiewicz]

• Operating system and version: ubuntu 16.04 LTS

With nvm 0.33.2 (and presumably trunk, the same code exists), I see the following error occasionally when using nvm inside a script with set -eu specified:

<snip>/.nvm/nvm.sh: line 3103: ALIAS: unbound variable

Command run: nvm ls 6

[alexjurkiewicz]

Related issue: #1505

[ljharb]

hmm, the code you linked to has the variable set here, which should mean it's always bound.

[ljharb]

although I can repro it locally, so i'll figure it out shortly :-)

[alexjurkiewicz]

The issue is this snippet:

        if [ "${ALIAS-}" = '--' ]; then
          unset ALIAS
        fi

        nvm_list_aliases "${ALIAS}"

The unset line is (in some cases, I don't understand nvm well enough to know when the condition fires) removing the variable. A smaller test case:

$ cat test.sh
#!/bin/bash -u
a="3"
echo $a
unset a
echo $a
$ ./test.sh
3
./test.sh: line 5: a: unbound variable

[ljharb]

Thanks, turns out it's a simple fix.

[alexjurkiewicz]

Looking at the code in nvm_list_aliases, you can probably replace unset ALIAS with ALIAS=""...? That function looks defensively written :)

[alexjurkiewicz]

👍 thanks!