I was working in Phoenix/Elixir and created a function component for navbar, and got this issue:

Done in 38ms.
Compiling 1 file (.ex)
    error: undefined function sigil_p/2 (expected RankgistWeb.NavComponents to define such a function or for it to be imported, but none are available)
    │
 55 │                   href={~p"/users/log_out"}
    │                   ^^^^^^^^^^^^^^^^^^^^^^^^^
    │
    └─ (rankgist 0.1.0) lib/rankgist_web/components/nav_components.ex:55: RankgistWeb.NavComponents.main/1

    error: undefined function sigil_p/2 (expected RankgistWeb.NavComponents to define such a function or for it to be imported, but none are available)
    │
 45 │                 href={~p"/track-competitors"}
    │                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    │
    └─ (rankgist 0.1.0) lib/rankgist_web/components/nav_components.ex:45: RankgistWeb.NavComponents.main/1

    error: undefined function sigil_p/2 (expected RankgistWeb.NavComponents to define such a function or for it to be imported, but none are available)
    │
  8 │         <.link href={~p"/"} class="flex items-center space-x-3 rtl:space-x-reverse">
    │         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    │
    └─ (rankgist 0.1.0) lib/rankgist_web/components/nav_components.ex:8: RankgistWeb.NavComponents.main/1


== Compilation error in file lib/rankgist_web/components/nav_components.ex ==
** (CompileError) lib/rankgist_web/components/nav_components.ex: cannot compile module RankgistWeb.NavComponents (errors have been logged)

Compiling 1 file (.ex)
    error: undefined function sigil_p/2 (expected RankgistWeb.NavComponents to define such a function or for it to be imported, but none are available)
    │
 55 │                   href={~p"/users/log_out"}
    │                   ^^^^^^^^^^^^^^^^^^^^^^^^^
    │
    └─ (rankgist 0.1.0) lib/rankgist_web/components/nav_components.ex:55: RankgistWeb.NavComponents.main/1

    error: undefined function sigil_p/2 (expected RankgistWeb.NavComponents to define such a function or for it to be imported, but none are available)
    │
 45 │                 href={~p"/track-competitors"}
    │                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    │
    └─ (rankgist 0.1.0) lib/rankgist_web/components/nav_components.ex:45: RankgistWeb.NavComponents.main/1

    error: undefined function sigil_p/2 (expected RankgistWeb.NavComponents to define such a function or for it to be imported, but none are available)
    │
  8 │         <.link href={~p"/"} class="flex items-center space-x-3 rtl:space-x-reverse">
    │         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    │
    └─ (rankgist 0.1.0) lib/rankgist_web/components/nav_components.ex:8: RankgistWeb.NavComponents.main/1


== Compilation error in file lib/rankgist_web/components/nav_components.ex ==
** (CompileError) lib/rankgist_web/components/nav_components.ex: cannot compile module RankgistWeb.NavComponents (errors have been logged)

to fix the issue of sigil_p/2 being undefined:

defmodule LiveViewAppWeb.NavComponents do
  use Phoenix.Component
  use LiveViewAppWeb, :verified_routes

  def main(assigns) do
    ~H"""...

use LiveViewAppWeb, :verified_routes adding this fixed it.