Description of problem:
When I try to build my software RPM, the build end by : (with rpmbuild -ba)

Processing files: CMU-MONITORING-3-0_12052003_15h46m51
Provides: libFileLockTools.so libReentrantTools.so libcmuclient.so libcmucomms.s
o libcmucomms_udp.so libcmudebug.so libcmufile.so libcmulineparser.so libcmuserv
er.so libcmutools.so libpthreadTools.so
Requires(interp): /bin/sh /bin/sh
Requires(rpmlib): rpmlib(CompressedFileNames) <= 3.0.4-1 rpmlib(PayloadFilesHave
Prefix) <= 4.0-1
Requires(post): /bin/sh
Requires(preun): /bin/sh
Requires: /bin/sh libFileLockTools.so libReentrantTools.so libc.so.6 libc.so.6(G
LIBC_2.0) libc.so.6(GLIBC_2.1) libc.so.6(GLIBC_2.1.2) libc.so.6(GLIBC_2.1.3) lib
c.so.6(GLIBC_2.3.2) libcmucomms.so libcmucomms_udp.so libcmudebug.so libcmufile.
so libcmulineparser.so libpthread.so.0 libpthread.so.0(GLIBC_2.0) libpthread.so.
0(GLIBC_2.1) libpthreadTools.so
Checking for unpackaged file(s): /usr/lib/rpm/check-files %{buildroot}
getOutputFrom(): Broken pipe

The problem is note systematic: when running 100 times the command it works 
about 2 times ?????
The packages can be build fine on redhat 7.3, 7.2 and 8.0

Version-Release number of selected component (if applicable):
rpm-build-4.2-0.69

How reproducible:
98 times out of 100

Steps to Reproduce:
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Actual results:


Expected results:


Additional info: