diff --git a/tool/run/boot_dir/fiasco b/tool/run/boot_dir/fiasco
index 54bde03ce..fa76ab81d 100644
--- a/tool/run/boot_dir/fiasco
+++ b/tool/run/boot_dir/fiasco
@@ -106,5 +106,13 @@ proc run_boot_dir {binaries} {
 ##
 # Base source archive within depot
 #
-proc base_src { } { return base-fiasco }
+proc base_src { } {
 
+	if {[have_spec x86_32]} { return base-fiasco }
+
+	global specs
+
+	puts stderr "Test requires base-fiasco kernel archive, which is missing for this build configuration"
+	puts stderr "  SPECS=\"$specs\""
+	exit 0
+}
diff --git a/tool/run/boot_dir/foc b/tool/run/boot_dir/foc
index b69e605a9..fe218bc29 100644
--- a/tool/run/boot_dir/foc
+++ b/tool/run/boot_dir/foc
@@ -213,5 +213,13 @@ proc run_boot_dir {binaries} {
 ##
 # Base source archive within depot
 #
-proc base_src { } { return base-foc }
+proc base_src { } {
 
+	if {[have_spec x86]} { return base-foc }
+
+	global specs
+
+	puts stderr "Test requires base-foc kernel archive, which is missing for this build configuration"
+	puts stderr "  SPECS=\"$specs\""
+	exit 0
+}
diff --git a/tool/run/boot_dir/hw b/tool/run/boot_dir/hw
index 92c3dc3b6..71fd6272d 100644
--- a/tool/run/boot_dir/hw
+++ b/tool/run/boot_dir/hw
@@ -202,9 +202,12 @@ proc run_boot_dir {binaries} {
 #
 proc base_src { } {
 
-	if {[have_spec x86_64]} { return base-hw-pc }
-	if {[have_spec pbxa9]}  { return base-hw-pbxa9 }
+	if {[have_spec x86_64] && ![have_spec muen]} { return base-hw-pc }
+	if {[have_spec pbxa9]}                       { return base-hw-pbxa9 }
 
-	puts stderr "base-hw kernel does not support this build configuration"
-	exit 1
+	global specs
+
+	puts stderr "Test requires base-hw kernel archive, which is missing for this build configuration"
+	puts stderr "  SPECS=\"$specs\""
+	exit 0
 }
diff --git a/tool/run/boot_dir/nova b/tool/run/boot_dir/nova
index 0e861bdc8..fd17ca0dc 100644
--- a/tool/run/boot_dir/nova
+++ b/tool/run/boot_dir/nova
@@ -135,5 +135,13 @@ proc run_boot_dir {binaries} {
 ##
 # Base source archive within depot
 #
-proc base_src { } { return base-nova }
+proc base_src { } {
 
+	if {[have_spec x86]} { return base-nova }
+
+	global specs
+
+	puts stderr "Test requires base-nova kernel archive, which is missing for this build configuration"
+	puts stderr "  SPECS=\"$specs\""
+	exit 0
+}
diff --git a/tool/run/boot_dir/okl4 b/tool/run/boot_dir/okl4
index e8d64454d..69981006f 100644
--- a/tool/run/boot_dir/okl4
+++ b/tool/run/boot_dir/okl4
@@ -203,5 +203,13 @@ proc run_boot_dir {binaries} {
 ##
 # Base source archive within depot
 #
-proc base_src { } { return base-okl4 }
+proc base_src { } {
 
+	if {[have_spec x86_32]} { return base-okl4 }
+
+	global specs
+
+	puts stderr "Test requires base-okl4 kernel archive, which is missing for this build configuration"
+	puts stderr "  SPECS=\"$specs\""
+	exit 0
+}
diff --git a/tool/run/boot_dir/pistachio b/tool/run/boot_dir/pistachio
index 375a44de1..842618215 100644
--- a/tool/run/boot_dir/pistachio
+++ b/tool/run/boot_dir/pistachio
@@ -103,5 +103,13 @@ proc run_boot_dir {binaries} {
 ##
 # Base source archive within depot
 #
-proc base_src { } { return base-pistachio }
+proc base_src { } {
 
+	if {[have_spec x86_32]} { return base-pistachio }
+
+	global specs
+
+	puts stderr "Test requires base-pistachio kernel archive, which is missing for this build configuration"
+	puts stderr "  SPECS=\"$specs\""
+	exit 0
+}
diff --git a/tool/run/boot_dir/sel4 b/tool/run/boot_dir/sel4
index 802cb3647..d824fe97a 100644
--- a/tool/run/boot_dir/sel4
+++ b/tool/run/boot_dir/sel4
@@ -142,5 +142,13 @@ proc run_boot_dir {binaries} {
 ##
 # Base source archive within depot
 #
-proc base_src { } { return base-sel4 }
+proc base_src { } {
 
+	if {[have_spec x86]} { return base-sel4 }
+
+	global specs
+
+	puts stderr "Test requires base-sel4 kernel archive, which is missing for this build configuration"
+	puts stderr "  SPECS=\"$specs\""
+	exit 0
+}