table of contents
|KYUA-DEBUG(1)||General Commands Manual||KYUA-DEBUG(1)|
kyua debug —
Executes a single test case with facilities for
kyua debug command provides a
mechanism to execute a single test case bypassing some of the Kyua
infrastructure and allowing the user to poke into the execution behavior of
The test case to run is selected by providing a test filter, described below in Test filters, that matches a single test case. The test case is executed and its result is printed as the last line of the output of the tool.
The test executed by
kyua debug is run
under a controlled environment as described in
At the moment, the
kyua debug command
allows the following aspects of a test case execution to be tweaked:
- Redirection of the test case's stdout and stderr to the console (the
default) or to arbitrary files. See the
The following subcommand options are recognized:
- Specifies the build root in which to find the test programs referenced by the Kyuafile, if different from the Kyuafile's directory. See Build directories below for more information.
- Specifies the Kyuafile to process. Defaults to Kyuafile file in the current directory.
- Specifies the file to which to send the standard error of the test program's body. The default is /dev/stderr, which is a special character device that redirects the output to standard error on the console.
- Specifies the file to which to send the standard output of the test program's body. The default is /dev/stdout, which is a special character device that redirects the output to standard output on the console.
For example, consider the following Kyua session:
$ kyua test kernel/fs:mkdir -> passed kernel/fs:rmdir -> failed: Invalid argument 1/2 passed (1 failed)
At this point, we do not have a lot of information regarding the
failure of the ‘kernel/fs:rmdir’ test. We can run this test
kyua debug command to inspect its output
a bit closer, hoping that the test case is kind enough to log its
$ kyua debug kernel/fs:rmdir Trying rmdir('foo') Trying rmdir(NULL) kernel/fs:rmdir -> failed: Invalid argument
Luckily, the offending test case was printing status lines as it progressed, so we could see the last attempted call and we can know match the failure message to the problem.
Build directories (or object directories, target directories, product directories, etc.) is the concept that allows a developer to keep the source tree clean from build products by asking the build system to place such build products under a separate subtree.
Most build systems today support build directories. For example, the GNU Automake/Autoconf build system exposes such concept when invoked as follows:
$ cd my-project-1.0 $ mkdir build $ cd build $ ../configure $ make
Under such invocation, all the results of the build are left in the my-project-1.0/build/ subdirectory while maintaining the contents of my-project-1.0/ intact.
Because build directories are an integral part of most build
systems, and because they are a tool that developers use frequently,
kyua debug supports build directories too. This
manifests in the form of
kyua debug being able to
run tests from build directories while reading the (often immutable) test
suite definition from the source tree.
One important property of build directories is that they follow (or need to follow) the exact same layout as the source tree. For example, consider the following directory listings:
src/Kyuafile src/bin/ls/ src/bin/ls/Kyuafile src/bin/ls/ls.c src/bin/ls/ls_test.c src/sbin/su/ src/sbin/su/Kyuafile src/sbin/su/su.c src/sbin/su/su_test.c obj/bin/ls/ obj/bin/ls/ls* obj/bin/ls/ls_test* obj/sbin/su/ obj/sbin/su/su* obj/sbin/su/su_test*
Note how the directory layout within src/ matches that of obj/. The src/ directory contains only source files and the definition of the test suite (the Kyuafiles), while the obj/ directory contains only the binaries generated during a build.
All commands that deal with the workspace support the
--build-root path option. When
this option is provided, the directory specified by the option is considered
to be the root of the build directory. For example, considering our previous
fake tree layout, we could invoke
kyua debug as any
of the following:
$ kyua debug --kyuafile=src/Kyuafile --build-root=obj $ cd src && kyua debug --build-root=../obj
A test filter is a string that is used to match test cases or test programs in a test suite. Filters have the following form:
Where ‘test_program_name’ is the name of a test program or a subdirectory in the test suite, and ‘test_case_name’ is the name of a test case.
The test programs and test cases run by
debug are all executed in a deterministic environment. This known,
clean environment serves to make the test execution as reproducible as
possible and also to prevent clashes between tests that may, for example,
create auxiliary files with overlapping names.
For plain test programs and for TAP test programs, the whole test program is run under a single instance of the environment described in this page. For ATF test programs (see atf(7)), each individual test case and test cleanup routine are executed in separate environments.
- Process space
- Each test is executed in an independent processes. Corollary: the test can do whatever it wants to the current process (such as modify global variables) without having to undo such changes.
- Session and process group
- The test is executed in its own session and its own process group. There
is no controlling terminal attached to the session.
Should the test spawn any children, the children should maintain the same session and process group. Modifying any of these settings prevents
kyua debugfrom being able to kill any stray subprocess as part of the cleanup phase. If modifying these settings is necessary, or if any subprocess started by the test decides to use a different process group or session, it is the responsibility of the test to ensure those subprocesses are forcibly terminated during cleanup.
- Work directory
- The test is executed in a temporary directory automatically created by the runtime engine. Corollary: the test can write to its current directory without needing to clean any files and/or directories it creates. The runtime engine takes care to recursively delete the temporary directories after the execution of a test case. Any file systems mounted within the temporary directory are also unmounted.
- Home directory
- The HOME environment variable is set to the absolute path of the work directory.
- The value of the umask is set to 0022.
- The LANG, LC_ALL,
LC_NUMERIC and LC_TIME
variables are unset.
The TZ variable is set to ‘UTC’.
The TMPDIR variable is set to the absolute path of the work directory. This is to prevent the test from mistakenly using a temporary directory outside of the automatically-managed work directory, should the test use the mktemp(3) familiy of functions.
- Process limits
- The maximum soft core size limit is raised to its corresponding hard limit. This is a simple, best-effort attempt at allowing tests to dump core for further diagnostic purposes.
- Configuration varibles
- The test engine may pass run-time configuration variables to the test program via the environment. The name of the configuration variable is prefixed with ‘TEST_ENV_’ so that a configuration variable of the form ‘foo=bar’ becomes accessible in the environment as ‘TEST_ENV_foo=bar’.
kyua debug command returns 0 if the
test case passes or 1 if the test case fails.
Additional exit codes may be returned as described in kyua(1).
|October 13, 2014||Debian|