=> Bootstrap dependency digest>=20010302: found digest-20160304
=> Fetching strace-4.5.15.tar.bz2
=> Total size: 455607 bytes
Certificate verification failed for /C=US/O=Let's Encrypt/CN=Let's Encrypt Authority X3
34374371912:error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed:/usr/src/crypto/openssl/ssl/s3_clnt.c:1269:
fetch: http://downloads.sourceforge.net/sourceforge/strace/strace-4.5.15.tar.bz2: Authentication error
fetch: Unable to fetch expected file strace-4.5.15.tar.bz2
strace-4.5.15.tar.bz2                                    0  B    0  Bps
=> Checksum SHA1 OK for strace-4.5.15.tar.bz2
=> Checksum RMD160 OK for strace-4.5.15.tar.bz2
=> Checksum SHA512 OK for strace-4.5.15.tar.bz2