NAME | DESCRIPTION | GATHERING MORE INFORMATION | SEE ALSO | COLOPHON
error::pass2 - systemtap pass-2 errors
Errors that occur during pass 2 (elaboration) can have a variety of causes. Common types include: missing debuginfo The script requires debuginfo to resolve a probe point, but could not find any. See error::dwarf(7stap) and warning::debuginfo(7stap) for more details. unavailable probe point classes Some types of probe points are only available on certain system versions, architectures, and configurations. For example, user-space process.* probes may require utrace or uprobes capability in the kernel for this architecture. unavailable probe points Some probe points may be individually unavailable even when their class is fine. For example, kprobe.function("foobar") may fail if function foobar does not exist in the kernel any more. Debugging or symbol data may be absent for some types of .function or .statement probes; check for availability of debuginfo. Try the stap-prep program to download possibly-required debuginfo. Use a wildcard parameter such as stap -l 'kprobe.function("*foo*")' to locate still-existing variants. Use ! or ? probe point suffixes to denote optional / preferred-alternatives, to let the working parts of a script continue. typos There might be a spelling error in the probe point name ("sycsall" vs. "syscall"). Wildcard probes may not find a match at all in the tapsets. Recheck the names using stap -l PROBEPOINT. Another common mistake is to use the . operator instead of the correct -> when dereferencing context variable subfields or pointers: $foo->bar->baz even if in C one would say foo->bar.baz. unavailable context variables Systemtap scripts often wish to refer to variables from the context of the probed programs using $variable notation. These variables may not always be available, depending on versions of the compiler, debugging/optimization flags used, architecture, etc. Use stap -L PROBEPOINT to list available context variables for given probes. Use the @defined() expression to test for the resolvability of a context variable expression. Consider using the stap --skip-badvars option to silently replace misbehaving context variable expressions with zero. Experiment with the stap --prologue-searching option. module cache inconsistencies Occasionally, the systemtap module cache ($HOME/.systemtap/cache) might contain obsolete information from a prior system configuration/version, and produce false results as systemtap attempts to reuse it. Retrying with stap --poison-cache ... forces new information to be generated. Note: this should not happen and likely represents a systemtap bug. Please report it.
Increasing the verbosity of pass-2 with an option such as --vp 02 can help pinpoint the problem.
stap(1), stap-prep(1), stapprobes(3stap), probe::*(3stap), error::dwarf(7stap), error::inode-uprobes(7stap), warning::debuginfo(7stap), error::reporting(7stap)
This page is part of the systemtap (a tracing and live-system analysis tool) project. Information about the project can be found at ⟨https://sourceware.org/systemtap/⟩. If you have a bug report for this manual page, send it to firstname.lastname@example.org. This page was obtained from the project's upstream Git repository ⟨git://sourceware.org/git/systemtap.git⟩ on 2022-12-17. (At that time, the date of the most recent commit that was found in the repository was 2022-12-16.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which is not part of the original manual page), send a mail to email@example.com ERROR::PASS2(7stap)