travis-build: preserving the status in $?

[grooverdan]

Whether make succeeds or fails $? is always 1.

script:
  - make -j 4
  - COMPILE_RESULT=$?
  - echo COMPILE_RESULT=${COMPILE_RESULT}

output:

..
The command "make -j 4" exited with 0.

$ COMPILE_RESULT=$?
The command "COMPILE_RESULT=$?" exited with 0.

$ echo COMPILE_RESULT=${COMPILE_RESULT}
COMPILE_RESULT=1

[BanzaiMan]

Each line in the script section is processed by the travis_cmd bash function. (The value 1 comes from the immediately preceding test [[ -n "$retry" ]] on line 38.)

I understand the motivation for using $? this way (and potentially other special variables) in the script section, but achieving it without breaking the currently working builds may be hard.

I tend to think it is better to document this behavior, and advise writing a custom script if the user wants to do something involving $? in the script section.

[grooverdan]

I think anyone who's tried to use $? has come across this limitation and avoided it by writing a custom script (like I should be doing now). Thanks for the prompt response.

[BanzaiMan]

I've noted this in http://docs.travis-ci.com/user/customizing-the-build/#Note-on-%24%3F. (Improvement suggestions welcome!)

I'm closing this now.

[weitjong]

The trick is, you have to get it right after the command.

make -j4; export COMPILE_RESULT=$?

Though in my .travis.yml I usually just combine the command using "&&" or "||" bash operator or inside another if statement, so I don't really need to use $? explicitly to get the exit status of the earlier command. e.g.:

make -j4 && other-cmd-to-execute-when-make-was-successful

or

make -j4 || other-cmd-to-execute-when-make-was-failed

[grooverdan]

@BanzaiMan , while I'm still not convinced that there is a person using $? to extract the value of [[ -n "$retry" ]] the alternative for documentation is here:

- COMPILE_RESULT=0 ; make -j4 || COMPILE_RESULT=$?; expr $COMPILE_RESULT != 0
- [ $COMPILE_RESULT -ge 2 ] && echo makefile error

So the two objectives in deciding this structure where to make $COMPILE_RESULT have the value of the return and to give travis a true/false indicator of the result of the compile. @weitjong suggestions are of course valid (though export is excessive) however sometime additional flexibility is needed.

[BanzaiMan]

Improvement to the documentation is also welcome!

[ryasmi]

Thanks @weitjong 👍

[wiprodev]

Does Travis capture the non zero exit code for init scripts like sudo service xyz start ? In my case though the service fails to start it shows build successful.