The alpine builders print out a warning about sched_getaffinity() not working.
This causes the version check for the boot jdk to fail.
Patch the command to determine the version number to ignore any errors and warnings.

--- old/make/autoconf/boot-jdk.m4
+++ new/make/autoconf/boot-jdk.m4
@@ -74,7 +74,7 @@
           BOOT_JDK_FOUND=no
         else
           # Oh, this is looking good! We probably have found a proper JDK. Is it the correct version?
-          BOOT_JDK_VERSION=`"$BOOT_JDK/bin/java" -version 2>&1 | $HEAD -n 1`
+          BOOT_JDK_VERSION=`"$BOOT_JDK/bin/java" -version 2>&1 | $GREP version | $HEAD -n 1`
 
           # Extra M4 quote needed to protect [] in grep expression.
           [FOUND_CORRECT_VERSION=`$ECHO $BOOT_JDK_VERSION | $EGREP '\"10([\.+-].*)?\"|\"9([\.+-].*)?\"'`]