ERROR::PASS2(7stap)ERROR::PASS2(7stap)NAMEerror::pass2 - systemtap pass-2 errors
DESCRIPTION
Errors that occur during pass 2 (elaboration) can have a variety of
causes. Common types include:
unavailable probe points
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. Debugging or symbol data
may be absent for .function or .statement probes. Use the stap
-L option to list available probe points. Use the ! or ? probe
point suffixes to denote optional / preferred-alternatives, to
let the working parts of a script continue. Check for avail‐
ability of debuginfo.
typos There might be a spelling error in the probe point name ("syc‐
sall" vs. "syscall"). Wildcard probes may not find a match at
all in the tapsets. Recheck the names.
unavailable context variables
Systemtap scripts often wish to refer to variables from the con‐
text 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 the @defined() expression to test for the resolvabil‐
ity of a context variable expression. Consider using the stap
--skip-badvars option to silently replace misbehaving context
variable expressions with zero.
GATHERING MORE INFORMATION
Increasing the verbosity of pass-2 with an option such as --vp 02 can
help pinpoint the problem.
SEE ALSOstap(1), stapprobes(3stap), probe::*(3stap), error::dwarf(7stap), warn‐
ing::debuginfo(7stap), error::reporting(7stap)ERROR::PASS2(7stap)
