Mac Travis build output truncated, hiding build failure details

[derekbruening]

This just showed up on PR #4221 3 times in a row (every build there including a restart I tried):

https://travis-ci.com/github/DynamoRIO/dynamorio/jobs/304776211

4080[ 22%] Building C object suite/tests/CMakeFiles/tool.fib_plus.dir/__/__/clients/drcachesim/tests/fib_plus.c.o
4081[ 22%] Linking C executable bin/tool.fib_plus
4082[ 22%] Built target tool.fib_plus
4083[ 22%] 

It looks like something external is killing the build process.
Xref #4126 where the same thing was happening but there it was after 10
minutes: here it's only 1 minute in.

[derekbruening]

Wow, master has a compile failure from that PR #4421! So probably the problem is log buffering by Travis and not printing everything out?!? Possibly the tee in our script but why would it be non-deterministic?
https://travis-ci.com/github/DynamoRIO/dynamorio/jobs/304949581

4182[ 33%] Building ASM_NASM object suite/tests/CMakeFiles/client.drwrap-test.appdll.dir/drwrap-test.appdll.c_asm.asm.o
4183/Users/travis/build/DynamoRIO/dynamorio/build_debug-internal-64/suite/tests/drwrap-test.appdll.c_asm.asm:402: error: symbol `tailcall_tail' undefined
4184/Users/travis/build/DynamoRIO/dynamorio/build_debug-internal-64/suite/tests/drwrap-test.appdll.c_asm.asm:409: error: label `_tailcall_tail' changed during code generation [-w+error=label-redef-late]
4185make[2]: *** [suite/tests/CMakeFiles/client.drwrap-test.appdll.dir/drwrap-test.appdll.c_asm.asm.o] Error 1

[derekbruening]

This seems to be happening again. For PR #4292 the Mac build output just ends mid-build, even after re-run: https://travis-ci.com/github/DynamoRIO/dynamorio/jobs/332667228

Looking closely there is a build failure:

/Users/travis/build/DynamoRIO/dynamorio/core/unix/injector.c:221:17: error: unused variable 'ld_preload' [-Werror,-Wunused-variable]
    const char *ld_preload = NULL;
                ^
Users/travis/build/DynamoRIO/dynamorio/core/unix/injector.c:223:17: error: unused variable 'cur_preload' [-Werror,-Wunused-variable]
    const char *cur_preload = getenv("LD_PRELOAD");
                ^
/Users/travis/build/DynamoRIO/dynamorio/core/unix/injector.c:222:17: error: unused variable 'dr_ld_preload_libs' [-Werror,-Wunused-variable]
    const char *dr_ld_preload_libs = "libdynamorio.so libdrpreload.so";
                ^
/Users/travis/build/DynamoRIO/dynamorio/core/unix/injector.c:216:10: error: unused variable 'ld_preload_libs' [-Werror,-Wunused-variable]
    char ld_preload_libs[MAX_OPTIONS_STRING];

[abhinav92003]

Found some relevant Travis issues: travis-ci/travis-ci#8973 and travis-ci/travis-ci#6018, with some possible workarounds.

I tried using fcntl to clear status flag for stdout before the build, but that didn't help.

Adding sleep after script execution (or error) seems to do the trick. It gives Travis enough time to capture the complete log before the VM exits. It's not an ideal solution, but should work for now.