So, I did as you suggested Max, and I can now do builds using either 2.0.0-rc1 or the earlier version that I used previously (and worked). Upload seems successful for both, but neither image runs properly 
Here is my ini file for the original toolchain and the pinned version of arduino-esp32:
[env:esp32c3]
platform = espressif32
platform_packages =
toolchain-riscv-esp
framework-arduinoespressif32@https://github.com/espressif/arduino-esp32.git#cbcba53
platformio/tool-esptoolpy @ ~1.30100
framework = arduino
board = esp32dev
board_build.mcu = esp32c3
board_build.partitions = huge_app.csv
board_build.variant = esp32c3
board_build.f_cpu = 160000000L
board_build.f_flash = 80000000L
board_build.flash_mode = qio
board_build.arduino.ldscript = esp32c3_out.ld
build_unflags =
-DARDUINO_ESP32_DEV
-DARDUINO_VARIANT="esp32"
build_flags =
-DARDUINO_ESP32C3_DEV
-DARDUINO_VARIANT="esp32c3"
Here are the upload logs using the old toolchain for some very basic test code:
/usr/local/bin/platformio -c clion run --target upload -e esp32c3
Processing esp32c3 (platform: espressif32; framework: arduino; board: esp32dev)
Tool Manager: Installing git+https://github.com/espressif/arduino-esp32.git#cbcba53
git version 2.26.0
Cloning into '/Users/bob/.platformio/.cache/tmp/pkg-installing-buxepb7o'...
remote: Enumerating objects: 26402, done.
remote: Counting objects: 100% (594/594), done.
remote: Compressing objects: 100% (324/324), done.
remote: Total 26402 (delta 221), reused 594 (delta 221), pack-reused 25808
Receiving objects: 100% (26402/26402), 746.70 MiB | 5.68 MiB/s, done.
Resolving deltas: 100% (16083/16083), done.
Updating files: 100% (6497/6497), done.
Updating files: 100% (1272/1272), done.
HEAD is now at cbcba53d Improve error message when ADC2 can not be used because WiFi is On
Tool Manager: framework-arduinoespressif32 @ 0.0.0+sha.cbcba53d has been installed!
Verbose mode can be enabled via `-v, --verbose` option
CONFIGURATION: https://docs.platformio.org/page/boards/espressif32/esp32dev.html
PLATFORM: Espressif 32 (3.3.1) > Espressif ESP32 Dev Module
HARDWARE: ESP32C3 160MHz, 320KB RAM, 4MB Flash
DEBUG: Current (esp-prog) External (esp-prog, iot-bus-jtag, jlink, minimodule, olimex-arm-usb-ocd, olimex-arm-usb-ocd-h, olimex-arm-usb-tiny-h, olimex-jtag-tiny, tumpa)
PACKAGES:
- framework-arduinoespressif32 0.0.0+sha.cbcba53d
- tool-esptoolpy 1.30100.210531 (3.1.0)
- tool-mkspiffs 2.230.0 (2.30)
- toolchain-riscv-esp 1.80400.0 (8.4.0)
LDF: Library Dependency Finder -> http://bit.ly/configure-pio-ldf
LDF Modes: Finder ~ chain, Compatibility ~ soft
Found 33 compatible libraries
Scanning dependencies...
No dependencies
Building in release mode
Compiling .pio/build/esp32c3/src/main.cpp.o
Generating partitions .pio/build/esp32c3/partitions.bin
Archiving .pio/build/esp32c3/libFrameworkArduinoVariant.a
Indexing .pio/build/esp32c3/libFrameworkArduinoVariant.a
Compiling .pio/build/esp32c3/FrameworkArduino/Esp.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/FunctionalInterrupt.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/HardwareSerial.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/IPAddress.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/IPv6Address.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/MD5Builder.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/Print.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/Stream.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/StreamString.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/USB.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/USBCDC.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/WMath.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/WString.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/base64.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/cbuf.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-adc.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-bt.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-cpu.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-dac.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-gpio.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-i2c.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-ledc.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-matrix.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-misc.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-psram.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-rmt.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-sigmadelta.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-spi.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-time.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-timer.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-tinyusb.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-touch.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/esp32-hal-uart.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/libb64/cdecode.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/libb64/cencode.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/main.cpp.o
Compiling .pio/build/esp32c3/FrameworkArduino/stdlib_noniso.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/wiring_pulse.c.o
Compiling .pio/build/esp32c3/FrameworkArduino/wiring_shift.c.o
Archiving .pio/build/esp32c3/libFrameworkArduino.a
Indexing .pio/build/esp32c3/libFrameworkArduino.a
Linking .pio/build/esp32c3/firmware.elf
Retrieving maximum program size .pio/build/esp32c3/firmware.elf
Checking size .pio/build/esp32c3/firmware.elf
Advanced Memory Usage is available via "PlatformIO Home > Project Inspect"
RAM: [ ] 2.9% (used 9392 bytes from 327680 bytes)
Flash: [= ] 6.6% (used 206692 bytes from 3145728 bytes)
Building .pio/build/esp32c3/firmware.bin
esptool.py v3.1
Merged 1 ELF section
Configuring upload protocol...
AVAILABLE: esp-prog, espota, esptool, iot-bus-jtag, jlink, minimodule, olimex-arm-usb-ocd, olimex-arm-usb-ocd-h, olimex-arm-usb-tiny-h, olimex-jtag-tiny, tumpa
CURRENT: upload_protocol = esptool
Looking for upload port...
Auto-detected: /dev/cu.usbserial-A50285BI
Uploading .pio/build/esp32c3/firmware.bin
esptool.py v3.1
Serial port /dev/cu.usbserial-A50285BI
Connecting....
Chip is unknown ESP32-C3 (revision 3)
Features: Wi-Fi
Crystal is 40MHz
MAC: 7c:df:a1:a4:49:7c
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
Configuring flash size...
Auto-detected Flash size: 4MB
Flash will be erased from 0x00000000 to 0x00004fff...
Flash will be erased from 0x00008000 to 0x00008fff...
Flash will be erased from 0x0000e000 to 0x0000ffff...
Flash will be erased from 0x00010000 to 0x00042fff...
Flash params set to 0x002f
Compressed 18864 bytes to 11763...
Writing at 0x00000000... (100 %)
Wrote 18864 bytes (11763 compressed) at 0x00000000 in 0.6 seconds (effective 255.3 kbit/s)...
Hash of data verified.
Compressed 3072 bytes to 119...
Writing at 0x00008000... (100 %)
Wrote 3072 bytes (119 compressed) at 0x00008000 in 0.1 seconds (effective 384.8 kbit/s)...
Hash of data verified.
Compressed 8192 bytes to 47...
Writing at 0x0000e000... (100 %)
Wrote 8192 bytes (47 compressed) at 0x0000e000 in 0.1 seconds (effective 588.7 kbit/s)...
Hash of data verified.
Compressed 207072 bytes to 99511...
Writing at 0x00010000... (14 %)
Writing at 0x0001a546... (28 %)
Writing at 0x000211ec... (42 %)
Writing at 0x000279b3... (57 %)
Writing at 0x0002f416... (71 %)
Writing at 0x0003a8b6... (85 %)
Writing at 0x00041fb6... (100 %)
Wrote 207072 bytes (99511 compressed) at 0x00010000 in 3.5 seconds (effective 474.1 kbit/s)...
Hash of data verified.
Leaving...
Hard resetting via RTS pin...
[SUCCESS] Took 176.74 seconds
Process finished with exit code 0
When I try to run this, I get this looping output in serial:
ESP-ROM:esp32c3-api1-20210207
Build:Feb 7 2021
rst:0x1 (POWERON),boot:0xf (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:QIO, clock div:1
load:0x3fcd6100,len:0x14b0
ets_loader.c 78
I’m using hardware that previously worked.
I realise I may be straying in ESP32 support rather than PlatformIO support, but I know the environment worked previously so I think what I have is still a PlatformIO configuration problem. Maybe.