m jpm trees rather than a system default by passing the <code class="mendoza-code">--tree=&lt;somewhere&gt;</code> argument
all jpm commands or setting the <code class="mendoza-code">JANET_TREE</code> environment variable. This will set the location
where jpm will install modules, headers, scripts, and other data to. For project local development in
a tree <code class="mendoza-code">./jpm_tree</code>, you can use the <code class="mendoza-code">--local</code> or <code class="mendoza-code">-l</code> shorthand