openjdk21 build errors

[Mayuresh <mayuresh%acm.org@localhost>]

On NetBSD 10.1 amd64 with a recent pkgsrc,

with no options enabled i.e.:

    These options are enabled by default:
            jdk-hotspot-vm jre-jce x11
    
    These options are currently enabled:
    
There are several warnings of this kind:

    Warning:
    The input uses the SHA1withRSA signature algorithm which is considered a security risk.
    Certificate was added to keystore 
    Certificate was added to keystore
    ...
    
    Warning:
    The input uses the SHA1withRSA signature algorithm which is considered a security risk.

Followed by this error:

    Runnable configure script is not present
    Generating runnable configure script at /usr/pkgsrc/work/lang/openjdk21/work/jdk21u-jdk-21.0.5-11-1/build/.
    configure-support/generated-configure.sh
    Using autoconf at /usr/pkgsrc/work/lang/openjdk21/work/.tools/bin/autoconf [autoconf (GNU Autoconf) 2.72]
    configure exiting with result code 1

    configure: error: unrecognized options: --with-libiconv-prefix

At this point if I simply re-run make it leads to these errors:

    ERROR: [check-portability.awk] => Found test ... == ...:
    ERROR: [check-portability.awk] build/.configure-support/generated-configure.sh:50596:   if test "x$RESULT" == "x"; then
    ERROR: [check-portability.awk] build/.configure-support/generated-configure.sh:71071:         if test "x$ISLINK" == x; then
    ERROR: [check-portability.awk] build/.configure-support/generated-configure.sh:81229:   if test "x$with_cacerts_file" == x; then
    ERROR: [check-portability.awk] build/.configure-support/generated-configure.sh:81255:   if test "x$with_cacerts_src" == x; then
    ERROR: [check-portability.awk] build/.configure-support/generated-configure.sh:86665:         if test "x$ISLINK" == x; then
    ERROR: [check-portability.awk] build/.configure-support/generated-configure.sh:89507:         if test "x$ISLINK" == x; then
    ERROR: [check-portability.awk] build/.configure-support/generated-configure.sh:135924:               if test "x${ipath:0:2}" == "x-I"; then
    ERROR: [check-portability.awk] build/.configure-support/generated-configure.sh:138635:               if test "x${ipath:0:2}" == "x-I"; then
    ERROR: [check-portability.awk] build/.configure-support/generated-configure.sh:143675:       if test "x$SYSROOT" != "x" && test "x${with_alsa_lib}" == x; then

Please advise.

-- 
Mayuresh