What causes "No rule to make target 'crypto/(0x55ae24c35998).o'"

[Jeffrey Walton]

Hi Everyone,

I'm working with OpenSSL sources, and trying to port OpenSSL tomodern
Android NDKs. I'm not familiar with their makefiles) other than they
are messy). My fork is at
https://github.com/noloader/openssl/tree/android.

The Travis jobs are failing with an error like shown below. An error
result is at https://travis-ci.org/github/noloader/openssl/jobs/661708091.

aarch64-linux-android26-clang  -I. -Iinclude -Iapps/include  -fPIC -pthread -Wa,
--noexecstack -Qunused-arguments -funwind-tables -fexceptions --sysroot=/home/tr
avis/android-ndk/toolchains/llvm/prebuilt/linux-x86_64/sysroot -DOPENSSL_USE_NOD
ELETE -DOPENSSL_BUILDING_OPENSSL -DOPENSSL_PIC -DOPENSSLDIR="\"/home/travis/andr
oid26-aarch64\"" -DENGINESDIR="\"/home/travis/android26-aarch64/lib/engines-3\""
 -DMODULESDIR="\"/home/travis/android26-aarch64/lib/ossl-modules\"" -DNDEBUG -D_
_ANDROID_API__=26 -MMD -MF apps/lib/libapps-lib-s_socket.d.tmp -MT apps/lib/liba
pps-lib-s_socket.o -c -o apps/lib/libapps-lib-s_socket.o apps/lib/s_socket.c

make[1]: *** No rule to make target 'crypto/(0x55ae24c35998).o',
needed by 'libcrypto.a'.  Stop.

The error message is the first mention of 0x55ae24c35998. It does not
show up in a compile command.

What causes a "No rule to make target 'crypto/(0x55ae24c35998).o'" error?

Thanks in advance.

Jeff