inding-sym">fiber/new</span> <span class="binding-type">cfunction</span> <span class="binding-type"><a href="https://github.com/janet-lang/janet/blob/3a4d56a/src/core/fiber.c#L505">source</a></span> <pre class="binding-text">(fiber/new func &amp;opt sigmask env)

Create a new fiber with function body func. Can optionally take a set of signals `sigmask` to capture from child fibers, and an environment table `env`. The mask is specified as a keyword where each character is used to indicate a signal to block. 