launch-ue5-project

Launch a UE5 project

Projects in this ecosystem launch the Unreal Editor through a repo-root launch-project.sh. That script kills a stale editor, cleans Live-Coding hot-reload dylib residue (stale versioned UnrealEditor-*-<n>.dylib files crash the editor on class registration), headlessly pre-builds a missing plugin dylib (the editor's modal "rebuild missing modules" path is unreliable on macOS), then nohup-launches the editor detached. Reproducing those steps by hand is the common way to a crashed or hung editor — always go through the script.

Procedure

digraph {
  "launch-project.sh at repo root?" [shape=diamond];
  "Run it" [shape=box];
  "Ask user: create one?" [shape=diamond];
  "Scaffold from template, then run" [shape=box];
  "Stop — report, don't guess a launch cmd" [shape=box];
  "launch-project.sh at repo root?" -> "Run it" [label="yes"];
  "launch-project.sh at repo root?" -> "Ask user: create one?" [label="no"];
  "Ask user: create one?" -> "Scaffold from template, then run" [label="yes"];
  "Ask user: create one?" -> "Stop — report, don't guess a launch cmd" [label="no"];
}

1. Locate

From the project repo root, check for ./launch-project.sh. It lives at the repo root even when the .uproject sits in a subdir (e.g. SampleProject/).

2. If it exists — run it

Run ./launch-project.sh (or bash ./launch-project.sh). It returns after printing Editor PID: <n>. A missing plugin dylib triggers a headless UBT build first, so allow up to ~10 min (long Bash timeout, or background it). Report the printed PID. Do not block waiting on the GUI and do not substitute your own UnrealEditor … invocation.

3. If it's missing — offer to create it

Ask the user whether to create launch-project.sh (do not create it unprompted). Only if they agree: copy launch-project.template.sh (in this skill's directory) to the repo root as launch-project.sh, chmod +x it, and fill the # >>> FILL placeholders by inspecting the project:

Placeholder	Where to get it
PROJECT_SUBDIR	repo-relative dir holding the .uproject (. if at root) — find . -name '*.uproject'
UPROJECT_BASENAME	the .uproject filename without extension
UE_VERSION	EngineAssociation in the .uproject, else EngineVersion in the plugin .uplugin (e.g. 5.7)
PLUGIN_NAME	the source plugin under Plugins/<Name>/ whose dylib needs rebuilds; leave "" for content/Blueprint-only projects

Then run it (step 2).

Scope / don't

• macOS only — the template's UE_EDITOR path is macOS. For Windows/Linux, say so and stop rather than improvise a launcher.
• Don't move/rename the project or hand-roll an UnrealEditor command "to save a step" — the residue cleanup and headless pre-build exist precisely because skipping them crashes the editor.
• Don't create the script without explicit user agreement.