perl-Crypt-OpenSSL-PKCS10-0.15-3.fc26 fails to build in F26: gcc -c -D_REENTRANT -D_GNU_SOURCE -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m32 -march=i686 -mtune=atom -fasynchronous-unwind-tables -fwrapv -fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -g -DVERSION=\"0.15\" -DXS_VERSION=\"0.15\" -fPIC "-I/usr/lib/perl5/CORE" -DPERL5 -Wall PKCS10.c [...] PKCS10.xs:439:10: error: dereferencing pointer to incomplete type 'EVP_PKEY {aka struct evp_pkey_st}' if (pkey->type == EVP_PKEY_RSA) { ^~ This is caused by upgrading openssl from 1:1.0.2j-1.fc26 to 1:1.1.0b-1.fc26.
I developed a fix and posted it to the upstream bug report.
The fix was accepted and released in 0.16 version.