diff --git a/src/cmd/diodcli.c b/src/cmd/diodcli.c
index 67eaf20b..ab16eb65 100644
--- a/src/cmd/diodcli.c
+++ b/src/cmd/diodcli.c
@@ -45,6 +45,7 @@
 #include <inttypes.h>
 #include <string.h>
 #include <getopt.h>
+#include <libgen.h>
 #if HAVE_SYS_XATTR_H
 #include <sys/xattr.h>
 #else
diff --git a/src/cmd/test/flock_single.c b/src/cmd/test/flock_single.c
index daa677ea..cbb01b81 100644
--- a/src/cmd/test/flock_single.c
+++ b/src/cmd/test/flock_single.c
@@ -13,6 +13,9 @@
 #if HAVE_CONFIG_H
 #include "config.h"
 #endif
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 #include <unistd.h>
 #include <sys/file.h>
 #include <stdlib.h>
diff --git a/src/libdiod/diod_sock.c b/src/libdiod/diod_sock.c
index 48b0bca7..12a80f8a 100644
--- a/src/libdiod/diod_sock.c
+++ b/src/libdiod/diod_sock.c
@@ -333,27 +333,34 @@ diod_sock_accept_one (Npsrv *srv, int fd, int lookup)
             err ("accept");
         return;
     }
-    if ((res = getnameinfo ((struct sockaddr *)&addr, addr_size,
-                            ip, sizeof(ip), svc, sizeof(svc),
-                            NI_NUMERICHOST | NI_NUMERICSERV))) {
-        msg ("getnameinfo: %s", gai_strerror(res));
-        close (fd);
-        return;
+    /* N.B. although glibc getnameinfo() sets ip to "localhost" for
+     * AF_UNIX, musl libc fails with EAI_FAMILY.  Hence, getnameinfo() is
+     * only attempted for non-AF_UNIX.  See also chaos/diod#160
+     */
+    if (addr.ss_family == AF_UNIX) {
+        if (!lookup || gethostname (host, sizeof (host)) < 0)
+            snprintf (host, sizeof (host), "localhost");
     }
-    if (addr.ss_family != AF_UNIX) {
+    else {
+        if ((res = getnameinfo ((struct sockaddr *)&addr, addr_size,
+                                ip, sizeof(ip), svc, sizeof(svc),
+                                NI_NUMERICHOST | NI_NUMERICSERV))) {
+            msg ("getnameinfo: %s", gai_strerror(res));
+            close (fd);
+            return;
+        }
+        if (lookup && (res = getnameinfo ((struct sockaddr *)&addr, addr_size,
+                                          host, sizeof(host), NULL, 0, 0))) {
+            msg ("getnameinfo: %s", gai_strerror(res));
+            close (fd);
+            return;
+        }
+        port = strtoul (svc, NULL, 10);
+        if (port < IPPORT_RESERVED && port >= IPPORT_RESERVED / 2)
+            flags |= CONN_FLAGS_PRIVPORT;
         (void)_disable_nagle (fd);
         (void)_enable_keepalive (fd);
     }
-    host[0] = '\0';
-    if (lookup && (res = getnameinfo ((struct sockaddr *)&addr, addr_size,
-                                      host, sizeof(host), NULL, 0, 0))) {
-        msg ("getnameinfo: %s", gai_strerror(res));
-        close (fd);
-        return;
-    }
-    port = strtoul (svc, NULL, 10);
-    if (port < IPPORT_RESERVED && port >= IPPORT_RESERVED / 2)
-        flags |= CONN_FLAGS_PRIVPORT;
     diod_sock_startfd (srv, fd, fd, strlen(host) > 0 ? host : ip, flags);
 }
 
diff --git a/t/sharness.d/10-sudo.sh b/t/sharness.d/10-sudo.sh
index 6f13a233..2e22ce25 100644
--- a/t/sharness.d/10-sudo.sh
+++ b/t/sharness.d/10-sudo.sh
@@ -3,12 +3,15 @@
 ##
 if sudo --non-interactive true >/dev/null 2>&1; then
     test_set_prereq SUDO
+    SUDO="sudo -E"
+elif _probeenv=xyz doas -n printenv _probeenv >/dev/null 2>&1; then
+    test_set_prereq SUDO
+    SUDO="doas"
 fi
 ##
 # Fixup sudo commandline if sanitizers are enabled.
 # LSan doesn't work under setuid or program run under sudo
 ##
-SUDO=sudo
 if test_have_prereq ASAN; then
-    SUDO="sudo -E ASAN_OPTIONS=$ASAN_OPTIONS:detect_leaks=0"
+    SUDO="ASAN_OPTIONS=$ASAN_OPTIONS:detect_leaks=0 $SUDO"
 fi
diff --git a/t/t0001-basic-runasuser.t b/t/t0001-basic-runasuser.t
index 3484466e..153f0137 100755
--- a/t/t0001-basic-runasuser.t
+++ b/t/t0001-basic-runasuser.t
@@ -54,11 +54,11 @@ test_expect_success 'copy ctl:/zero to ctl:null' '
 # implemented directly in libnpfs, bypassing diod_ops.c, where op_attach()
 # gates access to all other exports.
 test_expect_success SUDO 'the root user can access ctl:/version' '
-	$SUDO -E $PATH_DIODCLI --aname=ctl read version
+	$SUDO $PATH_DIODCLI --aname=ctl read version
 '
 
 test_expect_success NOBODY 'the nobody user can access ctl:/version' '
-	$SUDO -E -u nobody $PATH_DIODCLI --aname=ctl read version
+	$SUDO -u nobody $PATH_DIODCLI --aname=ctl read version
 '
 
 test_expect_success 'ls net:/ shows test files' '
@@ -87,13 +87,13 @@ test_expect_success 'cat net:/1/c produced test file content' '
 '
 
 test_expect_success SUDO 'cat net:/1/c fails as root' '
-	test_must_fail $SUDO -E \
+	test_must_fail $SUDO \
 	    $PATH_DIODCLI --aname=$exportdir read /1/c 2>rootcat.err &&
 	grep "Operation not permitted" rootcat.err
 '
 
 test_expect_success NOBODY 'cat net:/1/c fails as nobody' '
-	test_must_fail $SUDO -E -u nobody \
+	test_must_fail $SUDO -u nobody \
 	    $PATH_DIODCLI --aname=$exportdir read /1/c \
 	        2>nobodycat.err &&
 	grep "Operation not permitted" nobodycat.err
diff --git a/t/t0002-basic-allsquash.t b/t/t0002-basic-allsquash.t
index 7cd7606c..984d3d3b 100755
--- a/t/t0002-basic-allsquash.t
+++ b/t/t0002-basic-allsquash.t
@@ -29,21 +29,21 @@ test_expect_success 'the squash user can access ctl:/version' '
 '
 
 test_expect_success SUDO 'the root user can access ctl:/version' '
-	$SUDO -E $PATH_DIODCLI --aname=ctl read version
+	$SUDO $PATH_DIODCLI --aname=ctl read version
 '
 
 test_expect_success NOBODY 'the nobody user can access ctl:/version' '
-	$SUDO -E -u nobody $PATH_DIODCLI  --aname=ctl read version
+	$SUDO -u nobody $PATH_DIODCLI  --aname=ctl read version
 '
 
 test_expect_success 'the squash user can access net:/a' '
 	$PATH_DIODCLI --aname=$exportdir read /a
 '
 test_expect_success SUDO 'the root user can access net:/a' '
-	$SUDO -E $PATH_DIODCLI --aname=$exportdir read /a
+	$SUDO $PATH_DIODCLI --aname=$exportdir read /a
 '
 test_expect_success NOBODY 'the nobody user can access net:/a' '
-	$SUDO -E -u nobody $PATH_DIODCLI --aname=$exportdir read /a
+	$SUDO -u nobody $PATH_DIODCLI --aname=$exportdir read /a
 '
 
 test_expect_success 'stop diod' '
diff --git a/t/t0003-basic-multiuser.t b/t/t0003-basic-multiuser.t
index 226d5408..ed3ea568 100755
--- a/t/t0003-basic-multiuser.t
+++ b/t/t0003-basic-multiuser.t
@@ -47,43 +47,43 @@ test_expect_success 'the squash user can access ctl:/version' '
 	$PATH_DIODCLI --aname=ctl read version
 '
 test_expect_success 'the root user can access ctl:/version' '
-	$SUDO -E $PATH_DIODCLI --aname=ctl read version
+	$SUDO $PATH_DIODCLI --aname=ctl read version
 '
 test_expect_success 'the nobody user can access ctl:/version' '
-	$SUDO -E -u nobody $PATH_DIODCLI --aname=ctl read version
+	$SUDO -u nobody $PATH_DIODCLI --aname=ctl read version
 '
 
 test_expect_success 'user can access net:/user' '
 	$PATH_DIODCLI --aname=$exportdir read /user
 '
 test_expect_success 'nobody cannot access net:/user' '
-	test_must_fail $SUDO -E -u nobody \
+	test_must_fail $SUDO -u nobody \
 	    $PATH_DIODCLI --aname=$exportdir read /user
 '
 test_expect_success 'root can access net:/user' '
-	$SUDO -E $PATH_DIODCLI --aname=$exportdir read /user
+	$SUDO $PATH_DIODCLI --aname=$exportdir read /user
 '
 
 test_expect_success 'user cannot access net:/nobody' '
 	test_must_fail $PATH_DIODCLI --aname=$exportdir read /nobody
 '
 test_expect_success 'nobody can access net:/nobody' '
-	$SUDO -E -u nobody \
+	$SUDO -u nobody \
 	    $PATH_DIODCLI --aname=$exportdir read /nobody
 '
 test_expect_success 'root can access net:/nobody' '
-	$SUDO -E $PATH_DIODCLI --aname=$exportdir read /nobody
+	$SUDO $PATH_DIODCLI --aname=$exportdir read /nobody
 '
 
 test_expect_success 'user cannot access net:/root' '
 	test_must_fail $PATH_DIODCLI --aname=$exportdir read /root
 '
 test_expect_success 'nobody cannot access net:/root' '
-	test_must_fail $SUDO -E -u nobody \
+	test_must_fail $SUDO -u nobody \
 	    $PATH_DIODCLI --aname=$exportdir read /root
 '
 test_expect_success 'root can access net:/root' '
-	$SUDO -E $PATH_DIODCLI --aname=$exportdir read /root
+	$SUDO $PATH_DIODCLI --aname=$exportdir read /root
 '
 
 test_expect_success 'stop diod' '
diff --git a/t/t0010-v9fs-runasuser.t b/t/t0010-v9fs-runasuser.t
index b308915d..2e4c5590 100755
--- a/t/t0010-v9fs-runasuser.t
+++ b/t/t0010-v9fs-runasuser.t
@@ -30,7 +30,7 @@ test_under_diod unixsocket \
 
 # gnome probes for .Trash, autorun.inf, etc asynchronously on new mounts,
 # causing umount to fail with EBUSY if still in progress.  Therefore --lazy.
-umountcmd="$SUDO umount --lazy"
+umountcmd="$SUDO umount -l"
 mountcmd="$SUDO mount -n -t 9p"
 mountopts="trans=unix,uname=$(id -un)"
 
@@ -83,9 +83,10 @@ test_expect_success 'mount filesystem with access=<uid> on mnt' '
 	$mountcmd -oaname=$exportdir,$mountopts,access=$(id -u) \
 	    $DIOD_SOCKET mnt
 '
+# On alpine/busybox, %T decodes as type=UNKNOWN.  Use %t instead.
 test_expect_success STAT 'file system type is v9fs' '
-	echo v9fs >type.exp &&
-	stat -f -c "%T" mnt >type.out &&
+	echo 1021997 >type.exp &&
+	stat -f -c "%t" mnt >type.out &&
 	test_cmp type.exp type.out
 '
 test_expect_success STAT 'client/server mount point stats match' '
diff --git a/t/t0011-v9fs-allsquash.t b/t/t0011-v9fs-allsquash.t
index 73ae2baa..78a42a8e 100755
--- a/t/t0011-v9fs-allsquash.t
+++ b/t/t0011-v9fs-allsquash.t
@@ -27,7 +27,7 @@ test_under_diod unixsocket \
 
 # gnome probes for .Trash, autorun.inf, etc asynchronously on new mounts,
 # causing umount to fail with EBUSY if still in progress.  Therefore --lazy.
-umountcmd="$SUDO umount --lazy"
+umountcmd="$SUDO umount -l"
 mountcmd="$SUDO mount -n -t 9p"
 mountopts="trans=unix,uname=$(id -un)"
 
@@ -50,8 +50,12 @@ test_expect_success SUDO,STAT 'root can create a directory, mode 755' '
 	$SUDO mkdir -m 755 mnt/rootdir &&
 	test "$($PATH_STAT -c "%u:%g" exp/rootdir)" = "$(id -u):$(id -g)"
 '
+# N.B. fails on alpine/busybox when mkdir -m 755 is used because alpine
+# calls mkdir and chmod separately, so the chmod isn't allowed.
+# Do the chmod as the squashuser instead.
 test_expect_success NOBODY,STAT 'nobody can create a directory, mode 755' '
-	$SUDO -u nobody mkdir -m 755 mnt/nobodydir &&
+	$SUDO -u nobody mkdir mnt/nobodydir &&
+	chmod 755 mnt/nobodydir &&
 	test "$($PATH_STAT -c "%u:%g" exp/nobodydir)" = "$(id -u):$(id -g)"
 '
 
diff --git a/t/t0012-v9fs-multiuser.t b/t/t0012-v9fs-multiuser.t
index b2cdb0ce..11dd32e9 100755
--- a/t/t0012-v9fs-multiuser.t
+++ b/t/t0012-v9fs-multiuser.t
@@ -38,7 +38,7 @@ fi
 
 # gnome probes for .Trash, autorun.inf, etc asynchronously on new mounts,
 # causing umount to fail with EBUSY if still in progress.  Therefore --lazy.
-umountcmd="$SUDO umount --lazy"
+umountcmd="$SUDO umount -l"
 mountcmd="$SUDO mount -n -t 9p"
 mountopts="trans=unix,uname=$(id -un)"
 
diff --git a/t/t0013-v9fs-acl.t b/t/t0013-v9fs-acl.t
index 3a5d6bd8..c1f97ae5 100755
--- a/t/t0013-v9fs-acl.t
+++ b/t/t0013-v9fs-acl.t
@@ -34,7 +34,7 @@ test_under_diod unixsocketroot \
 
 # gnome probes for .Trash, autorun.inf, etc asynchronously on new mounts,
 # causing umount to fail with EBUSY if still in progress.  Therefore --lazy.
-umountcmd="$SUDO umount --lazy"
+umountcmd="$SUDO umount -l"
 
 test_expect_success 'create export/mount directories' '
 	mkdir -p exp mnt
diff --git a/t/t0020-dbench.t b/t/t0020-dbench.t
index a9a549dc..93b03536 100755
--- a/t/t0020-dbench.t
+++ b/t/t0020-dbench.t
@@ -35,7 +35,7 @@ test_under_diod unixsocket \
 
 # gnome probes for .Trash, autorun.inf, etc asynchronously on new mounts,
 # causing umount to fail with EBUSY if still in progress.  Therefore --lazy.
-umountcmd="$SUDO umount --lazy"
+umountcmd="$SUDO umount -l"
 mountcmd="$SUDO mount -n -t 9p"
 mountopts="trans=unix,uname=$(id -un)"
 
diff --git a/t/t0021-postmark.t b/t/t0021-postmark.t
index f390da95..a13673c2 100755
--- a/t/t0021-postmark.t
+++ b/t/t0021-postmark.t
@@ -35,7 +35,7 @@ test_under_diod unixsocket \
 
 # gnome probes for .Trash, autorun.inf, etc asynchronously on new mounts,
 # causing umount to fail with EBUSY if still in progress.  Therefore --lazy.
-umountcmd="$SUDO umount --lazy"
+umountcmd="$SUDO umount -l"
 mountcmd="$SUDO mount -n -t 9p"
 mountopts="trans=unix,uname=$(id -un)"
 
diff --git a/t/t0022-scrub.t b/t/t0022-scrub.t
index 5e8c638c..9d8b0f51 100755
--- a/t/t0022-scrub.t
+++ b/t/t0022-scrub.t
@@ -34,7 +34,7 @@ test_under_diod unixsocket \
 
 # gnome probes for .Trash, autorun.inf, etc asynchronously on new mounts,
 # causing umount to fail with EBUSY if still in progress.  Therefore --lazy.
-umountcmd="$SUDO umount --lazy"
+umountcmd="$SUDO umount -l"
 mountcmd="$SUDO mount -n -t 9p"
 mountopts="trans=unix,uname=$(id -un)"
 
diff --git a/t/t0023-rsync.t b/t/t0023-rsync.t
index c7bea400..6a040e68 100755
--- a/t/t0023-rsync.t
+++ b/t/t0023-rsync.t
@@ -35,7 +35,7 @@ test_under_diod unixsocketroot \
 
 # gnome probes for .Trash, autorun.inf, etc asynchronously on new mounts,
 # causing umount to fail with EBUSY if still in progress.  Therefore --lazy.
-umountcmd="$SUDO umount --lazy"
+umountcmd="$SUDO umount -l"
 
 test_expect_success 'create export/mount directories' '
 	mkdir -p exp mnt
diff --git a/t/t0024-selfhost.t b/t/t0024-selfhost.t
index e09cd352..8c20eaf6 100755
--- a/t/t0024-selfhost.t
+++ b/t/t0024-selfhost.t
@@ -38,7 +38,7 @@ test_under_diod unixsocket \
 
 # gnome probes for .Trash, autorun.inf, etc asynchronously on new mounts,
 # causing umount to fail with EBUSY if still in progress.  Therefore --lazy.
-umountcmd="$SUDO umount --lazy"
+umountcmd="$SUDO umount -l"
 mountcmd="$SUDO mount -n -t 9p"
 mountopts="trans=unix,uname=$(id -un)"
 
diff --git a/t/t0025-pathwalk.t b/t/t0025-pathwalk.t
index 6d2fadf3..0561fc84 100755
--- a/t/t0025-pathwalk.t
+++ b/t/t0025-pathwalk.t
@@ -26,7 +26,7 @@ test_under_diod unixsocket \
 
 # gnome probes for .Trash, autorun.inf, etc asynchronously on new mounts,
 # causing umount to fail with EBUSY if still in progress.  Therefore --lazy.
-umountcmd="$SUDO umount --lazy"
+umountcmd="$SUDO umount -l"
 mountcmd="$SUDO mount -n -t 9p"
 mountopts="trans=unix,uname=$(id -un)"