The strace_helper code has a _make_error function to simplify making
StraceResult objects in error cases. That takes a details parameter
which is either a caught OSError or `bytes`. If it's bytes, _make_error
would implicitly coerce that to a str inside of a f-string, resulting in
a BytesWarning.
It's useful to see if it's an OSError or bytes when debugging, resolve
by changing to format with repr().
This is an error message on an internal helper.
A non-zero exit code occurs if the strace binary isn't found, and no
events will be parsed in that case (there is no output). Handle that
case by checking exit code before checking for events.
Still asserting around events rather than returning false, so that
hopefully if there's some change to `strace` that breaks the parsing,
will see that as a test failure rather than silently loosing strace
tests because they are auto-disabled.
`mmap`, `munmap`, and `mprotect` are used by CPython for memory
management, which may occur in the middle of the FileIO tests. The
system calls can also be used with files, so `strace` includes them
in its `%file` and `%desc` filters.
Filter out the `mmap` system calls related to memory allocation for the
file tests. Currently FileIO doesn't do `mmap` at all, so didn't add
code to track from `mmap` through `munmap` since it wouldn't be used.
For now if an `mmap` on a fd happens, the call will be included (which
may cause test to fail), and at that time support for tracking the
address throug `munmap` could be added.
Distribution tooling (ex. sandbox on Gentoo and fakeroot on Debian) uses
LD_PRELOAD to intercept system calls and potentially modify them when
building. These tools can change the set of system calls, so disable
system call testing under these cases.
Co-authored-by: Michał Górny <mgorny@gentoo.org>
Cody Maloney