getting the "os error 2" error when trying to write a trace

[Maoni0]

I'm getting these errors with the default cmdline record-trace --on-cpu -

2026-05-13T23:59:01.220665Z  WARN one_collect::helpers::exporting::os::linux: Unable to open perf-map file: pid=1, ns_pid=Some(1), error=No such file or directory (os error 2)
2026-05-13T23:59:01.220669Z  INFO one_collect::helpers::exporting::os::linux: Checking perf-map file: "/tmp/perf-3476.map"
2026-05-13T23:59:01.220793Z  WARN one_collect::helpers::exporting::os::linux: Unable to open perf-map file: pid=3476, ns_pid=Some(3476), error=No such file or directory (os error 2)

and it generates this

-rw-r--r-- 1 root root 3206 May 13 21:07 '>'

and it works if I specify the out dir with --out=./perfview_test_trace.

[brianrob]

I followed up with @Maoni0 offline on this - the issue is actually this:

2026-05-13T23:54:14.586238Z ERROR engine::export: NetTrace export failed: error=Is a directory (os error 21)

We need to make sure that when an output path isn't specified, that we don't try to write the file to the directory path and instead append the default file path to it. We should be pre-checking the output path, default or not, to make sure that writing will work and if it won't, we should fail early before starting to collect.