oak fails to link

[tcurdt]

Just trying to build a blink program I get the following link failure for the oak.

$ pio run -t upload
Processing oak (platform: espressif8266; board: oak; framework: arduino)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Verbose mode can be enabled via `-v, --verbose` option
CONFIGURATION: https://docs.platformio.org/page/boards/espressif8266/oak.html
PLATFORM: Espressif 8266 (3.2.0) > DigiStump Oak
HARDWARE: ESP8266 80MHz, 80KB RAM, 4MB Flash
PACKAGES: 
 - framework-arduinoespressif8266 3.30002.0 (3.0.2) 
 - tool-esptool 1.413.0 (4.13) 
 - tool-esptoolpy 1.30000.201119 (3.0.0) 
 - tool-mklittlefs 1.203.210628 (2.3) 
 - tool-mkspiffs 1.200.0 (2.0) 
 - toolchain-xtensa 2.100300.210717 (10.3.0)
LDF: Library Dependency Finder -> https://bit.ly/configure-pio-ldf
LDF Modes: Finder ~ chain, Compatibility ~ soft
Found 35 compatible libraries
Scanning dependencies...
No dependencies
Building in release mode
Linking .pio/build/oak/firmware.elf
/Users/tcurdt/.platformio/packages/toolchain-xtensa/bin/../lib/gcc/xtensa-lx106-elf/10.3.0/../../../../xtensa-lx106-elf/bin/ld: .pio/build/oak/libFrameworkArduino.a(core_esp8266_main.cpp.o):(.text._ZL12loop_wrapperv+0x8): undefined reference to `setup'
/Users/tcurdt/.platformio/packages/toolchain-xtensa/bin/../lib/gcc/xtensa-lx106-elf/10.3.0/../../../../xtensa-lx106-elf/bin/ld: .pio/build/oak/libFrameworkArduino.a(core_esp8266_main.cpp.o):(.text._ZL12loop_wrapperv+0xc): undefined reference to `loop'
/Users/tcurdt/.platformio/packages/toolchain-xtensa/bin/../lib/gcc/xtensa-lx106-elf/10.3.0/../../../../xtensa-lx106-elf/bin/ld: .pio/build/oak/libFrameworkArduino.a(core_esp8266_main.cpp.o): in function `_ZL12loop_wrapperv':
core_esp8266_main.cpp:(.text._ZL12loop_wrapperv+0x25): undefined reference to `setup'
/Users/tcurdt/.platformio/packages/toolchain-xtensa/bin/../lib/gcc/xtensa-lx106-elf/10.3.0/../../../../xtensa-lx106-elf/bin/ld: core_esp8266_main.cpp:(.text._ZL12loop_wrapperv+0x31): undefined reference to `loop'
collect2: error: ld returned 1 exit status
*** [.pio/build/oak/firmware.elf] Error 1