x signinfo?

wcfs/go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/kisielk/og-rek v1.2.0
 	github.com/pkg/errors v0.9.1
 	github.com/stretchr/testify v1.8.4
+	golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a // indirect
 	lab.nexedi.com/kirr/go123 v0.0.0-20230714134036-155506a9880e
 	lab.nexedi.com/kirr/neo/go v0.0.0-20230524100036-4c9414ea9a03
 )

wcfs/wcfs.go

@@ -509,6 +509,8 @@ import (
 	"github.com/hanwen/go-fuse/v2/fuse/nodefs"
 	"github.com/pkg/errors"
 
+	"golang.org/x/sys/unix"
+
 	"lab.nexedi.com/nexedi/wendelin.core/wcfs/internal/xzodb"
 	"lab.nexedi.com/nexedi/wendelin.core/wcfs/internal/zdata"
 )
@@ -1495,12 +1497,23 @@ func (w *Watch) _pin(ctx context.Context, blk int64, rev zodb.Tid) (err error) {
 			// access to which address generated this error going in si_addr field of
 			// siginfo structure. It would be good if we can mimic that behaviour to a
 			// reasonable extent if possible."
-			err := syscall.Kill(pid, syscall.Signal(syscall.SIGBUS))
+			//
+			// we need https://pkg.go.dev/golang.org/x/sys/unix#SignalfdSiginfo
+			// but there seems to be no API to use this struct?
+			//	=> wait, that's https://linux.die.net/man/2/signalfd
+			//         ('signalfd_siginfo'), which is different to siginfo_t,
+			//	   see https://man7.org/linux/man-pages/man2/sigaction.2.html	
+			//
+			// maybe we need to implement something similar to
+			//
+			//	https://cs.opensource.google/go/x/sys/+/refs/tags/v0.12.0:unix/zsyscall_linux.go;l=2106-2111
+			// ?
+			err := unix.Kill(pid, syscall.Signal(syscall.SIGBUS))
 			if err != nil {
 				return err
 			}
 			if isProcessAlive(pid, time.Second * 1) {
-				err = syscall.Kill(pid, syscall.Signal(syscall.SIGKILL))
+				err = unix.Kill(pid, syscall.Signal(syscall.SIGKILL))
 				if err != nil {
 					return err
 				}