syz-ci: disable CONFIG_DEBUG_INFO_BTF during patch testing

This is a hack as noted in the comment.
A proper support would require touching lots of files,
and we only need this temporary until #2096 is resolved.

One recent example of failed patch testing:
https://groups.google.com/g/syzkaller-bugs/c/O8CkScAt9ck/m/E3CYKSGSAgAJ

1 files changed, 11 insertions, 0 deletions

diff --git a/syz-ci/jobs.go b/syz-ci/jobs.go
index 3322609dd..cb6f2fe58 100644
--- a/syz-ci/jobs.go
+++ b/syz-ci/jobs.go
@@ -527,6 +527,17 @@ func (jp *JobProcessor) testPatch(job *Job, mgrcfg *mgrconfig.Config) error {
 		}
 	}
 
+	// Disable CONFIG_DEBUG_INFO_BTF in the config.
+	// DEBUG_INFO_BTF requires a very new pahole binary, which we don't have on syzbot instances.
+	// Currently we don't enable DEBUG_INFO_BTF, but we have some old bugs with DEBUG_INFO_BTF enabled
+	// (at the time requirements for pahole binary were lower, or maybe the config silently disabled itself).
+	// Testing of patches for these bugs fail now because of the config, so we disable it as a work-around.
+	// Ideally we have a new pahole and then we can remove this hack. That's issue #2096.
+	// pkg/vcs/linux.go also disables it for the bisection process.
+	req.KernelConfig = bytes.Replace(req.KernelConfig,
+		[]byte("CONFIG_DEBUG_INFO_BTF=y"),
+		[]byte("# CONFIG_DEBUG_INFO_BTF is not set"), -1)
+
 	log.Logf(0, "job: building kernel...")
 	kernelConfig, _, err := env.BuildKernel(mgr.mgrcfg.Compiler, mgr.mgrcfg.Ccache, mgr.mgrcfg.Userspace,
 		mgr.mgrcfg.KernelCmdline, mgr.mgrcfg.KernelSysctl, req.KernelConfig)