Print error messages from the forked process to stderr.

src/vdfp_pipe.c

@@ -34,6 +34,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <string.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <poll.h>
 #include <limits.h>
@@ -140,12 +141,11 @@ mk_pipe(int fds[2], char *name, struct vsl_log *vsl)
 }
 
 static inline int
-mk_dup(int oldfd, int newfd, char *name, struct vsl_log *vsl)
+mk_dup(int oldfd, int newfd)
 {
 	errno = 0;
 	if (dup2(oldfd, newfd) == -1) {
-		VSLb(vsl, SLT_Error, "vdfp_pipe: vdp %s: dup2(2) failed: %s",
-		     name, vstrerror(errno));
+		fprintf(stderr, "dup2(2) failed: %s", vstrerror(errno));
 		return (-1);
 	}
 	return (0);
@@ -239,18 +239,17 @@ vdp_init(struct req *req, void **priv)
 		closefd(&in[1]);
 		closefd(&out[0]);
 		closefd(&err[0]);
-		if (mk_dup(in[0], STDIN_FILENO, obj->name, req->vsl) != 0)
+		if (mk_dup(err[1], STDERR_FILENO) != 0)
 			exit(EXIT_FAILURE);
-		if (mk_dup(out[1], STDOUT_FILENO, obj->name, req->vsl) != 0)
+		if (mk_dup(in[0], STDIN_FILENO) != 0)
 			exit(EXIT_FAILURE);
-		if (mk_dup(err[1], STDERR_FILENO, obj->name, req->vsl) != 0)
+		if (mk_dup(out[1], STDOUT_FILENO) != 0)
 			exit(EXIT_FAILURE);
 
 		errno = 0;
 		if (execve(obj->path, argv, environ) == -1) {
-			VSLb(req->vsl, SLT_Error, "vdfp_pipe: vdp %s: cannot "
-			     "exec %s: %s", obj->name, obj->path,
-			     vstrerror(errno));
+			fprintf(stderr, "cannot exec %s: %s", obj->path,
+				vstrerror(errno));
 			exit(EXIT_FAILURE);
 		}
 	}