I upgraded to 1.8.8 today and now the guider is not longer working.
I am using the QHY CCD driver. When I try and capture I get a timeout error. The camera gives a "GetQHYCCDSingleFrame error (-1)" error.
Yup, I experienced the same issue (though I don't run stellarmate, nor update the way you do).
I happened to have an old machine with a working installation
See indilib.org/forum/general/8586-qhy-issues.html
I am running on Raspbian (november release) on a Raspberry Pi 4.
If that's you too, these are the files I used to update my drivers.
(Please backup, your originals, etc, and take care ...)
I replaced the 3 qhy libraries with the same names as the files in the below link in /usr/lib/arm-linux-gnueabiaf/ drive.google.com/drive/folders/1NtACfuZi...mjnnt7uC?usp=sharing
After doing that qhy_ccd_test and Ekos worked again with my QHY 5L-II mono camera.