Godot: Don't allow exporting a project if no main scene is defined

[LoneDespair]

Godot version:

godot 3.2.2-stable

OS/device including version:

Windows, gles2

Issue description:

When exporting a game with no selected main scene, exported game crashes on start

Steps to reproduce:
Not select a main scene and then export to windows

Minimal reproduction project:

[bojidar-bg]

What would be the expected behavior in this case?

[Zireael07]

IMHO not let you export, with a popup saying you don't have a main scene set.

[akien-mga]

When exporting a game with no selected main scene, exported game crashes on start

Does it crash, or does it fail to start and give an error? It should be the latter, which is not a bug (while an engine crash would be).

[girng]

Good catch. What @Zireael07 said is what I thought it already did O_o

[LoneDespair]

@akien-mga it just crashes with no popup error

[akien-mga]

Right, the above popup is when there's no .pck.

I would expect it to print an error if run in a terminal and terminate gracefully, not crash though.

[Calinou]

@LoneDespair Try starting the project from a command prompt. (On Windows, you'll need to export a debug build instead of a release build to see any kind of output.)

[LoneDespair]

@Calinou this was tested on a debug build
Although the terminal included in debug export seems to say something but the game crashes so fast, it's unreadable

tho this might be a issue for platforms with no terminal included in debug, eg mobile

[Calinou]

Although the terminal included in debug export seems to say something but the game crashes so fast, it's unreadable

This is why you can open a command prompt and start the binary there to read the output :slightly_smiling_face:

Godot doesn't bundle its own command prompt system (unlike a few other engines out there). It's just that debug Windows builds are compiled as console applications, causing Windows to open a command prompt automatically as long as the process is running.