Have configured sogo to authenticate through saml to a simplesamlphp backend. Accessing sogo redirects to idp login page and after correct login, idp redirects to SOGo/saml2-signon-post, where apache throws an error "Error reading from remote server".
Further looking in sogo.log, the error seems to be the termination of a child process with signal 11:
<0x0x56473396c310[WOWatchDogChild]> (terminated due to signal 11).
After installing *-debuginfo and running sogo inside gdb debugger (according to sogo how to debug guide) I get the same error on the web page, and gdb indicates a segmentation fault:

Feb 28 14:00:39 sogod [15937]: |SOGo| starting method 'GET' on uri '/SOGo/saml2-signon-post'
Feb 28 14:00:39 sogod [15937]: <0x0x5555558a4db0[SOGoCache]> Cache cleanup interval set every 300.000000 seconds
Feb 28 14:00:39 sogod [15937]: <0x0x5555558a4db0[SOGoCache]> Using host(s) 'localhost' as server(s)

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff4f4a7cf in objc_msg_lookup () from /lib64/libobjc.so.4

Also mentioning that the SAML IdP is configured with the attribute nameformat: urn:oasis:names:tc:SAML:2.0:attrname-format:uri and oid -> name conversion is being done, as indicated in the sogo configuration guide (settings for simplesamlphp).