ESP8266 V3.1.1 fails to build

[jantje]

ESP8266 V3.1.1 fails to build
This is caused by

recipe.hooks.prebuild.2.pattern="${runtime.tools.python3.path}/python3" -I "${runtime.tools.mkbuildoptglobals}" "${runtime.ide.path}" ${runtime.ide.version} "${build.path}" "${build.opt.fqfn}" "${globals.h.source.fqfn}" "${commonhfile.fqfn}" ${mkbuildoptglobals.extra_flags}
This because Sloeber assumes the hooks to start from 1 and here it starts from 2.

Note that -as we learned from other issues- the usage of the opt file decreases the user experience due to discovery problems because the discovery command fails due to a missing .opt file (created in the PREBUILD command only executed during build.

[jantje]

Workaround: in platform.txt change recipe.hooks.prebuild.2.pattern to recipe.hooks.prebuild.1.pattern
And then do the steps described here to clear the caching #1533

[jantje]

After fixing the fact that sloeber only picks up pre and post commands starting from 1 things became worse.
It seems the pre build command script has a dependency on preferences.txt and errors before copying the opt file.
The error was also caught by make who ended the build.
The script also uses the environment variable runtime.ide.path which was not implemented by Sloeber.
Fixing that in #1547 did not improve things.
I did find a way to make make ignore the error caused by the prebuild command.
I also improved the code to ignore .opt files (should also improve STM32 and ESP32 experiences)

So the current situation in the nightly is that

1. the workaround removes the opt file from the command line
2. the pre build command is taken into account but fails if arduino IDE is not installed in a supported way on the system. If it doesn't fail the standard opt file is copied to the build folder
3. The build command ignores the copied opt file

Therefore

1. The discovery does not fail due to missing opt file
2. A failing pre build command does not impact the build result
3. the opt file functionality is disabled and if you want this you need to go to project properties->sloeber and add the "@{my opt file}" to the necessary add to command line fields

The nightly works again so I close this issue as fixed in the nightly