How to run an existing version of Minecraft (already installed on my system) via headless-mc?

[Arc8ne]

As per the title, how do I launch an existing version of Minecraft that is already installed on my system via headless-mc?

[3arthqu4ke]

If it was installed by the official launcher it should be listed when you do versions. Then just launch <version>.

Now if you mean an official launcher profile or other launchers, HeadlessMc does not have support for that.

[Arc8ne]

What exactly are you looking for? Which launcher? Official Launcher profiles maybe, launching other launchers only as a plugin.

However, I was originally wondering if support for launching existing (locally installed) versions of Minecraft by specifying the path to the game JAR file could be added (rather than support for specific launchers).

[3arthqu4ke]

Will look into it. With game jar you mean like legacy versions, where the entire game is in one jar?

[Arc8ne]

Will look into it. With game jar you mean like legacy versions, where the entire game is in one jar?

Thank you and nope, I was referring to more recent versions of the game like 1.21.5 and 1.21.6 for instance though ideally version-agnostic support or support for all versions could be added.

[3arthqu4ke]

Hmm, you need to understand that modern versions are not launched from a single jar, but together with lots of other library jars. So I am not sure what you mean with a singular game jar for these new versions. What you could do, however, is to set the hmc.mcdir propery to specify the directory of where these libraries, assets and game jars are stored.

[Arc8ne]

Hmm, you need to understand that modern versions are not launched from a single jar, but together with lots of other library jars. So I am not sure what you mean with a singular game jar for these new versions. What you could do, however, is to set the hmc.mcdir propery to specify the directory of where these libraries, assets and game jars are stored.

I see, thanks for letting me know about that and sorry for the confusion lol. In that case, I was wondering if support for the PollyMC launcher (i.e. its way of organizing library jars and other file(s) for different versions) could be added?