There are couple issues with the new libdap version in rawhide, I've checked only s390x now, so they might be common with ppc or other arches (or not).

1. D4FilterClauseTest enters endless loop somewhere in argument parsing, workaround is to use -fsigned-char - it explains also the stuck build on 32-bit arm

[sharkcz@devel11 libdap-3.18.1]$ gdb
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(gdb) attach 34526
Attaching to process 34526
Reading symbols from /home/sharkcz/libdap/libdap-3.18.1/unit-tests/.libs/lt-D4FilterClauseTest...done.
Reading symbols from /home/sharkcz/libdap/libdap-3.18.1/.libs/libdap.so.23...done.
Reading symbols from /lib64/libpthread.so.0...(no debugging symbols found)...done.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Reading symbols from /lib64/libcrypto.so.10...Reading symbols from /lib64/libcrypto.so.10...(no debugging symbols found)...done.
(no debugging symbols found)...done.
Reading symbols from /lib64/libxml2.so.2...Reading symbols from /lib64/libxml2.so.2...(no debugging symbols found)...done.
(no debugging symbols found)...done.
Reading symbols from /lib64/libcppunit-1.13.so.0...Reading symbols from /lib64/libcppunit-1.13.so.0...(no debugging symbols found)...done.
(no debugging symbols found)...done.
Reading symbols from /lib64/libstdc++.so.6...(no debugging symbols found)...done.
Reading symbols from /lib64/libm.so.6...(no debugging symbols found)...done.
Reading symbols from /lib64/libgcc_s.so.1...(no debugging symbols found)...done.
Reading symbols from /lib64/libc.so.6...(no debugging symbols found)...done.
Reading symbols from /lib/ld64.so.1...(no debugging symbols found)...done.
Reading symbols from /lib64/libdl.so.2...(no debugging symbols found)...done.
Reading symbols from /lib64/libz.so.1...Reading symbols from /lib64/libz.so.1...(no debugging symbols found)...done.
(no debugging symbols found)...done.
Reading symbols from /lib64/liblzma.so.5...Reading symbols from /lib64/liblzma.so.5...(no debugging symbols found)...done.
(no debugging symbols found)...done.
GetOpt::operator() (this=0x3ffe55fe1b8) at GNU/GetOpt.cc:144
144	{
Missing separate debuginfos, use: dnf debuginfo-install cppunit-1.13.2-2.fc24.s390x glibc-2.24.90-1.fc26.s390x libgcc-6.1.1-4.fc25.s390x libstdc++-6.1.1-4.fc25.s390x libxml2-2.9.3-4.fc25.s390x openssl-libs-1.0.2h-2.fc25.s390x xz-libs-5.2.2-2.fc24.s390x zlib-1.2.8-10.fc24.s390x
(gdb) where
#0  GetOpt::operator() (this=0x3ffe55fe1b8) at GNU/GetOpt.cc:144
#1  0x000002aa30a03e4c in main (argc=<optimized out>, argv=0x3ffe55fe438) at D4FilterClauseTest.cc:571
(gdb) l
139	   If OPTSTRING starts with `-', it requests a different method of handling the
140	   non-option ARGV-elements.  See the comments about RETURN_IN_ORDER, above.  */
141	
142	int
143	GetOpt::operator () (void)
144	{
145	  if (nextchar == 0 || *nextchar == 0)
146	    {
147	      if (ordering == PERMUTE)
148	        {
(gdb) q
A debugging session is active.

	Inferior 1 [process 34526] will be detached.

Quit anyway? (y or n) y
Detaching from program: /home/sharkcz/libdap/libdap-3.18.1/unit-tests/.libs/lt-D4FilterClauseTest, process 34526


2. few tests failed

...
 91: trans ce test_array_3.1.dmr row;x test_array_3.1.dmr.1.trans_base FAILED (DMRTest.at:342)
 92: trans ce test_array_3.1.dmr row=[2:3];x test_array_3.1.dmr.2.trans_base FAILED (DMRTest.at:342)
 93: trans ce test_array_3.1.dmr row=[2:3];x[0:1] test_array_3.1.dmr.3.trans_base FAILED (DMRTest.at:342)
 94: trans ce test_array_3.1.dmr x[0:1] test_array_3.1.dmr.4.trans_base FAILED (DMRTest.at:342)
 95: trans ce test_array_3.1.dmr x test_array_3.1.dmr.5.trans_base FAILED (DMRTest.at:342)
...

might be new tests with missing big endian baseline, will check.


Version-Release number of selected component (if applicable):
libdap-3.18.1-1.fc26