HPMA115S0 dust sensor library

This library throws some typecast errors out of the box. I can get past the invalid conversion from 'const char' to 'unsigned char*' [-fpermissive] errors by changing

const char cmd[] = {0x68, 0x01, 0x01, 0x96};


unsigned char cmd[] = {0x68, 0x01, 0x01, 0x96};

But I’m left with line 83 in the library:

if (_serial.readStringUntil(HPM_CMD_RESP_HEAD)) {

throwing an conversion from 'String' to 'bool' is ambiguous error. I can’t figure this one out. Any suggestions?

This is due to a change in the system firmware which has broken this kind of check.
You need to write it the long way

 if (_serial.readStringUntil(HPM_CMD_RESP_HEAD) != "") {

This should have been addressed along with another issue in 0.8.0-rc.5 and we are now at 0.8.0-rc.11, so could you check if the original syntax is working with any version 0.8.0-rc.5+ and if not post a comment in this issue here