The browser-support interface includes sched_setscheduler when using ‘allow-sandbox: true’. This is often used when the application has the chromium content api’s sandbox enabled. If you adjust your snap to use:
plugs:
browser-sandbox:
interface: browser-support
allow-sandbox: true
apps:
chameleon:
plugs:
...
- browser-sandbox
then I suspect your snap will start working.
However, this will trigger a manual review in the store because use of the ‘allow-sandbox’ attribute of the browser-support interface is reserved for vetted publishers since it grants additional privileged accesses.
For regular electron apps, we advise disabling the internal chromium sandbox (use --no-sandbox) and just relying on the snapd sandbox and browser-support as you are using it now. For full blown browsers (eg, opera, brave, etc), we can perform publisher vetting and grant you use of browser-support with allow-sandbox: true, as described above.
Can you describe chameleon in more detail and how it might relate to other major browsers or to typical electron apps?