Jail error reporting is confusing

[nigoroll]

varnish-cache/bin/varnishd/mgt/mgt_jail.c

Line 151 in 45cdc60

i = vjt->make_workdir(dname, NULL, NULL);

if the jail implementation is present, the jail, for example

varnish-cache/bin/varnishd/mgt/mgt_jail_unix.c

Line 272 in 45cdc60

MGT_Complain(C_ERR, "Cannot create working directory '%s': %s",

generates an error message, and

varnish-cache/bin/varnishd/mgt/mgt_main.c

Lines 882 to 883 in 45cdc60

	ARGV_ERR("Cannot create working directory (%s): %s\n",
	workdir, VAS_errtxt(errno));

on top:

$ sudo /tmp/sbin/varnishd -j unix -n /tmp/ro/workdir -a @a -b @b
Error: zCannot create working directory '/tmp/ro/workdir': Read-only file system
Error: Cannot create working directory (/tmp/ro/workdir): Success
(-? gives usage)

If the jail implementation is not present, only the error from mgt_main.c is emitted:

$ sudo /tmp/sbin/varnishd -j none -n /tmp/ro/workdir -a @a -b @b
Error: Cannot create working directory '/tmp/ro/workdir': Read-only file system
(-? gives usage)

errror message changed with this patch:

diff --git a/bin/varnishd/mgt/mgt_jail_unix.c b/bin/varnishd/mgt/mgt_jail_unix.c
index 9ca2f234b..f3a3d3a77 100644
--- a/bin/varnishd/mgt/mgt_jail_unix.c
+++ b/bin/varnishd/mgt/mgt_jail_unix.c
@@ -269,7 +269,7 @@ vju_make_workdir(const char *dname, const char *what, struct vsb *vsb)
        AZ(seteuid(0));
 
        if (mkdir(dname, 0755) < 0 && errno != EEXIST) {
-               MGT_Complain(C_ERR, "Cannot create working directory '%s': %s",
+               MGT_Complain(C_ERR, "zCannot create working directory '%s': %s",
                    dname, VAS_errtxt(errno));
                return (1);
        }