Detected unknown package espressif8266_stage

I have been wrestling with Platformio for over a month with several problems on Win 10 64bit.

When I go to open a new project I get an error: detected unknown package espressif8266_stage.
When I try to build an existing project I get:‘xtensa-lx106-elf-g++’ is not recognized as an internal or external command,operable program or batch file.

When I “update platforms and libraries” it shows that espressif8266 and toolchain extensa are installed and up to date.
Any help?

Please correct platform option according to Espressif 8266 — PlatformIO v6.1 documentation

Thank you that got past the new project error … I am still wrestling with the :
When I try to build an existing project I get:‘xtensa-lx106-elf-g++’ is not recognized as an internal or external command,operable program or batch file.

When I “update platforms and libraries” it shows that espressif8266 and toolchain extensa are installed and up to date.
Any help?

I see this platform in IDE (all ESP8266 boards are listed twice) but not in CLI. Initializing project with espressif8266_stage fails as shown in image below.

$ pio platform list | grep "~"
atmelavr ~ Atmel AVR
espressif8266 ~ Espressif 8266
ststm32 ~ ST STM32

Thanks guys!!! That is my stupid mistake. I’ve just cleaned API cache.
Please run pio update and check pio boards.

New to pio. I am getting the same error Detected unknown package espressif8266_stage.

I installed staging using command:
platformio platform install GitHub - platformio/platform-espressif8266: Espressif 8266: development platform for PlatformIO
Here is the output:

PlatformManager: Installing platform-espressif8266
espressif8266 @ e75d211 is already installed
PackageManager: Installing toolchain-xtensa @ ~1.40802.0
toolchain-xtensa @ 1.40802.0 is already installed
PackageManager: Installing tool-esptool @ ~1.409.0
tool-esptool @ 1.409.0 is already installed
The platform ‘GitHub - platformio/platform-espressif8266: Espressif 8266: development platform for PlatformIO’ has been successfully installed!
The rest of packages will be installed automatically depending on your build environment.

but still getting the error. Where I am going wrong?

http://docs.platformio.org/en/latest/platforms/espressif8266.html#using-arduino-framework-with-staging-version

I think i followed the steps properly but still did not work as there are no errors in update.

Here is the result of pio update:

platformio platform update GitHub - platformio/platform-espressif8266: Espressif 8266: development platform for PlatformIO
Platform GitHub - platformio/platform-espressif8266: Espressif 8266: development platform for PlatformIO

Updating espressif8266 @ e75d211 [Up-to-date]
Updating framework-arduinoespressif8266 @ 1.20300.1 [Up-to-date]
Updating tool-esptool @ 1.409.0 [Up-to-date]
Updating toolchain-xtensa @ 1.40802.0 [Up-to-date]

pio platform uninstall espressif8266
pio platform install https://github.com/platformio/platform-espressif8266.git#feature/stage

Same issue here. I installed staging version using the quoted command, it installed under platforms/espressif8266@src-d2f6a4ecb96f34425e5e701de09dc0a9. But if I try to build my project with platform = espressif8266_stage, I get:

PlatformManager: Installing espressif8266_stage
Error: Detected unknown package 'espressif8266_stage'

Ah, I see. I should have used platform = espressif8266@4f59cef, i.e. take the version of platform from pio platform list command.

Answer is here