Build folder in sketch folder fails on second verify (spurious "build options changed")

[czgtest]

Repro on Arduino 1.8.7 and arduino-nightly-windows\arduino-nightly (latest Dec 6 )
OS : windows10

step:
1.download Arduino 1.8.7 or arduino-nightly
2.run verify command line

arduino_debug.exe --verify d:\test\test\1205\111\Blink_error\Blink_error\Blink.ino --board esp8266:esp8266:huzzah:CpuFrequency=80,VTable=flash,FlashSize=4M1M,LwIPVariant=v2mss536,Debug=Disabled,DebugLevel=None____,FlashErase=none,UploadSpeed=115200 --pref build.path=d:\test\test\1205\111\Blink_error\Blink_error\build12

the first time , the verify is pass

run verify command in second time , it will fail

it always fail due to sketch folder and build.options.json not delete.

[facchinm]

@czgtest build folder is inside sketch folder, right? We are seeing some similar reports on https://github.com/arduino/arduino-builder ; as a first step, I'll go on and change the title of the issue. In the meantime, make sure to build outside the sketch folder to avoid triggering this bug.

[czgtest]

Blink_error.zip

@facchinm attach the folder to you

[facchinm]

@czgtest I forgot that I already prepared a PR for this error 😄
Here it is arduino/arduino-builder#299

I'm going ahead and merge it so we'll release a build of arduino-builder soonish with this improvement (and it will be available in IDE hourly)