OpenIndiana has a different default location for certificates.

--- swipl-9.2.9/packages/ssl/ssl4pl.c.orig
+++ swipl-9.2.9/packages/ssl/ssl4pl.c
@@ -68,7 +68,7 @@
 
 #define SSL_CONFIG_MAGIC 0x539dbe3a
 #ifndef SYSTEM_CACERT_FILENAME
-#define SYSTEM_CACERT_FILENAME "/etc/ssl/certs/ca-certificates.crt"
+#define SYSTEM_CACERT_FILENAME "/etc/certs/ca-certificates.crt"
 #endif
 
 #define SSL_MAX_CERT_KEY_PAIRS 12
--- swipl-9.2.9/packages/ssl/CMakeLists.txt.orig
+++ swipl-9.2.9/packages/ssl/CMakeLists.txt
@@ -112,13 +112,14 @@
 
 if(NOT DEFINED SYSTEM_CACERT_FILENAME)
   set(CERT_CANDIDATES
+      /etc/certs/ca-certificates.crt
       /data/data/com.termux/files/usr/etc/tls/cert.pem
       /etc/ssl/certs/ca-certificates.crt
       /etc/pki/tls/certs/ca-bundle.crt
       /etc/ssl/ca-bundle.pem
       /etc/ssl/cert.pem)
 
-  set(SYSTEM_CACERT_FILENAME /etc/ssl/certs/ca-certificates.crt)
+  set(SYSTEM_CACERT_FILENAME /etc/certs/ca-certificates.crt)
   foreach(f ${CERT_CANDIDATES})
     if(EXISTS ${f})
       set(SYSTEM_CACERT_FILENAME ${f})