If you want to hot-swap I2C devices, you may need something like the PCA9511A chip.
Still, deleting the driver shouldn't crash a core - or at least there should be an easier approach.

Your read routine is missing the data register address. This code (mcp23008) is a little messy because of the error printing, but you can see that you need to send write the register address you want to read from, and then read the result. /***********************************************************...

oops ... no upload for .zip. Do you want the log?

Here's the log from msys32. New download, make clean; make defconfig all V=1 and it compiled fine After that - last part of log - I just did make clean; make menuconfig and make and the errors show up. Lesson learned, sort of ... I followed the steps in http://esp-idf.readthedocs.io/en/latest/window...

I didn't see the attach part until now .. I'll do that. I use OS-X and msys32 and both had that problem using the 'make clean, make menuconfig, make' routine I saw in the different docs. I tried your method and the only real difference in the commands, is that you use 'make -j8' where I was using ju...

@krzychb thanks for the reply ... If I download using git clone --recursive https://github.com/espressif/esp-idf.git and use the examples/peripheral/spi_master it compiles for me also. If, however, I download using the instructions git clone https://github.com/espressif/esp-idf.git esp-idf-v2.0-rc1 ...

The spi_master example seems to be broken. Were the examples updated with the v2.0?
Seems to be several errors involving phy defines
(e.g. esp-idf-v2.0-rc1/components/esp32/./phy_init.c:159: undefined reference to `phy_get_rf_cal_version')