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 ...

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 ...

@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 ...

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')