Repository: nvm
Issue: Cannot install node on OpenBSD
Labels: OS: FreeBSD / OpenBSD,installing node

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#### Operating system and version:
OpenBSD 6.6

#### `nvm debug` output:
<details>
<!-- do not delete the following blank line -->

```sh
nvm --version: v0.35.1
$SHELL: /usr/local/bin/zsh
$SHLVL: 2
${NVM_DIR}: '${HOME}/.nvm'
$PREFIX: ''
${NPM_CONFIG_PREFIX}: ''
$NVM_NODEJS_ORG_MIRROR: ''
$NVM_IOJS_ORG_MIRROR: ''
shell version: 'zsh 5.7.1 (x86_64-unknown-openbsd6.6)'
uname -a: 'OpenBSD 6.6 GENERIC.MP#510 amd64'
curl: /usr/local/bin/curl, curl 7.67.0 (x86_64-unknown-openbsd6.6) libcurl/7.67.0 LibreSSL/3.0.2 zlib/1.2.3 nghttp2/1.40.0
wget: not found
git: /usr/local/bin/git, git version 2.24.0
ls: grep:: No such file or directory
grep: grep: aliased to grep  (grep), grep version 0.9
awk: /usr/bin/awk, awk: unknown option --version ignored
sed: /usr/bin/sed, sed: unknown option -- -
cut: /usr/bin/cut, cut: unknown option -- -
basename: /usr/bin/basename, basename: unknown option -- -
rm: /bin/rm, rm: unknown option -- -
mkdir: /bin/mkdir, mkdir: unknown option -- -
xargs: /usr/bin/xargs, xargs: unknown option -- -
nvm current: system
which node: /usr/local/bin/node
which iojs: iojs not found
which npm: /usr/local/bin/npm
npm config get prefix: /usr/local
npm root -g: /usr/local/lib/node_modules
```
</details>

#### `nvm ls` output:
<details>
<!-- do not delete the following blank line -->

```sh
->       system
iojs -> N/A (default)
node -> stable (-> N/A) (default)
unstable -> N/A (default)
lts/* -> lts/erbium (-> N/A)
lts/argon -> v4.9.1 (-> N/A)
lts/boron -> v6.17.1 (-> N/A)
lts/carbon -> v8.16.2 (-> N/A)
lts/dubnium -> v10.17.0 (-> N/A)
lts/erbium -> v12.13.1 (-> N/A)

```
</details>

#### How did you install `nvm`?
<!-- (e.g. install script in readme, Homebrew) -->
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.1/install.sh | bash

#### What steps did you perform?
nvm install 12

#### What happened?
tar does not recognize -J
```
Can not determine how many core(s) are available, running in single-threaded mode.                                                                                            
Please report an issue on GitHub to help us make nvm run faster on your computer!                                                                                             
Clang v3.5+ detected! CC or CXX not specified, will use Clang as C/C++ compiler!                                                                                              
Downloading https://nodejs.org/dist/v12.13.1/node-v12.13.1.tar.xz...                                                                                                          
####################################################################################################################################################################### 100.0%
Computing checksum with sha256 -q                                                                                                                                             
Checksums matched!                                                                                                                                                            
tar: unknown option -- J                                                                                                                                                      
usage: tar {crtux}[014578befHhjLmNOoPpqsvwXZz]                                                                                                                                
           [blocking-factor | archive | replstr] [-C directory] [-I file]                                                                                                     
           [file ...]                                                                                                                                                         
       tar {-crtux} [-014578eHhjLmNOoPpqvwXZz] [-b blocking-factor]                    
           [-C directory] [-f archive] [-I file] [-s replstr] [file ...]
nvm: install v12.13.1 failed!
```

#### What did you expect to happen?
Successfully install node version 12

#### Is there anything in any of your profile files that modifies the `PATH`?
<!--  (e.g. `.bashrc`, `.bash_profile`, `.zshrc`, etc) -->
N/A