Index: library/lib/nx-test.tcl
===================================================================
diff -u -N -r5ab2ad98d7e3d8509a26ea32ec64fa9cc78af2f8 -r1d2bdbea2141f159f982e8dde0f9b0a6778a8b71
--- library/lib/nx-test.tcl	(.../nx-test.tcl)	(revision 5ab2ad98d7e3d8509a26ea32ec64fa9cc78af2f8)
+++ library/lib/nx-test.tcl	(.../nx-test.tcl)	(revision 1d2bdbea2141f159f982e8dde0f9b0a6778a8b71)
@@ -1,6 +1,10 @@
 package provide nx::test 1.0
 package require nx
 
+if {![llength [info commands try]]} {
+  package req try
+}
+
 namespace eval ::nx {
 
   # @file Simple regression test support for XOTcl / NX
Index: tests/contains.test
===================================================================
diff -u -N -ra2c877c7dd15b66e27dd85c9c17744670474d132 -r1d2bdbea2141f159f982e8dde0f9b0a6778a8b71
--- tests/contains.test	(.../contains.test)	(revision a2c877c7dd15b66e27dd85c9c17744670474d132)
+++ tests/contains.test	(.../contains.test)	(revision 1d2bdbea2141f159f982e8dde0f9b0a6778a8b71)
@@ -182,7 +182,8 @@
 set ::errorcode $::errorCode
 ? {set ::errorMsg} {somethingwrong}
 ? {set ::errorinfo} {somethingwrong
-    while executing
+    ::o ::nx::Object->contains
+    invoked from within
 "o contains { return -code error -errorcode {FOO bar baz} somethingwrong}"}
 ? {set ::errorcode} {FOO bar baz}
 
Index: tests/destroy.test
===================================================================
diff -u -N -r5ab2ad98d7e3d8509a26ea32ec64fa9cc78af2f8 -r1d2bdbea2141f159f982e8dde0f9b0a6778a8b71
--- tests/destroy.test	(.../destroy.test)	(revision 5ab2ad98d7e3d8509a26ea32ec64fa9cc78af2f8)
+++ tests/destroy.test	(.../destroy.test)	(revision 1d2bdbea2141f159f982e8dde0f9b0a6778a8b71)
@@ -2,6 +2,8 @@
 package require nx
 package require nx::test
 
+set ::tcl86 [package vsatisfies [package req Tcl] 8.6]
+
 nx::test configure -count 10
 
 ::nx::configure defaultMethodCallProtection false
@@ -161,7 +163,12 @@
   puts stderr "AAAA [current] exists [::nsf::object::exists [current]]"
   :set x 1
   #? "[current] set x" 1 "$::case can still access [current]"
-  ? "[current] set x" {TCL LOOKUP VARNAME x} "$::case cannot access [current]"
+
+  if {$::tcl86} {
+    ? "[current] set x" {TCL LOOKUP VARNAME x} "$::case cannot access [current]"
+  } else {
+    ? "[current] set x" {can't read "x": no such variable} "$::case cannot access [current]"
+  }
   ? {::nsf::object::exists c1} 1 "$::case object still exists in proc"
   #? "set ::firstDestroy" 0 "firstDestroy called"
   #? "set ::ObjectDestroy" 0 "ObjectDestroy called"
Index: tests/double-alias.tcl
===================================================================
diff -u -N
--- tests/double-alias.tcl	(revision df76a8d9ffa43e250f5cf6b82e229fa51dac3026)
+++ tests/double-alias.tcl	(revision 0)
@@ -1,173 +0,0 @@
-package prefer latest
-package require nx::test
-
-
-nx::test case alias-redefine-method1 {
-    #
-    # redefine an object method by an alias pointing to an alias
-    #
-    proc ::foo args {;}
-    
-    nx::Object create o
-    ? {::o public object method BAR {} {;}} ::o::BAR
-    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
-
-    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
-    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR exists"
-    ? {::nsf::method::alias o BAR ::o::bar} ::o::BAR "redefine an object method with an alias (pointing to an alias) 87a2"
-}
-
-nx::test case alias-redefine-method2 {
-    #
-    # redefine an object method by an alias pointing to an object method
-    #
-    proc ::foo args {;}
-    
-    nx::Object create o
-    ? {::o public object method BAR {} {;}} ::o::BAR
-    ? {::o public object method FOO {} {;}} ::o::FOO
-
-    ? {info commands ::o::FOO} ::o::FOO              "a command ::o::FOO exists"
-    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR exists"
-    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "redefine an object method with an alias (pointing to a method) 87a2"
-}
-
-
-nx::test case alias-double-alias-proc {
-
-    proc ::foo args {;}
-    nx::Object create o
-
-    ? {info commands ::o::FOO} ""                    "a command ::o::FOO' does not exist"
-    ? {info commands ::o::BAR} ""                    "a command ::o::BAR does not exist"
-    ? {::nsf::method::alias o FOO ::foo}    ::o::FOO "define an object alias based on existing ::foo"
-    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "define an object alias based on alias based on existing ::o::FOO"
-}
-
-nx::test case alias-double-alias-define {
-    #
-    # same as alias-double-reference-proc, but method instead of proc as target of o::FOO
-    #
-    proc ::foo args {;}
-
-    nx::Object create o
-    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
-
-    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
-    ? {info commands ::o::FOO} ""                    "a command ::o::FOO' does not exists"
-    ? {info commands ::o::BAR} ""                    "a command ::o::BAR does not exist"
-    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "define an object alias based on existing ::o::bar"
-    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "define an object alias based on alias based on existing (?) ::o::bar"
-}
-
-
-nx::test case alias-double-alias-redefine {
-    #
-    # same as alias-double-reference-define, but redefined instead of new definition
-    #
-    proc ::foo args {;}
-    
-    nx::Object create o
-    ? {::nsf::method::alias ::o FOO ::foo} ::o::FOO
-    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
-
-    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
-    ? {info commands ::o::FOO} ::o::FOO              "a command ::o::FOO' exists"
-    ? {info commands ::o::BAR} ""                    "a command ::o::BAR does not exist"
-    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "redefine an object alias based on existing ::o::bar"
-    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "define an object alias based on alias based on existing ::o::FOO"
-}
-
-nx::test case alias-double-alias-redefine0 {
-    #
-    # same as alias-double-reference-define, but redefined second cmd instead of new definition
-    #
-    proc ::foo args {;}
-    
-    nx::Object create o
-    ? {::o public object method BAR {} {;}} ::o::BAR
-    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
-
-    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
-    ? {info commands ::o::FOO} ""                    "a command ::o::FOO' does not exist"
-    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR exists"
-    ? {::nsf::method::alias o FOO ::foo} ::o::FOO    "define an object alias based on existing ::foo"
-    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "redefine an object alias based on alias based on existing ::o::FOO 87a2"
-}
-
-nx::test case alias-double-alias-redefine1 {
-    #
-    # same as alias-double-reference-define, but redefined second cmd instead of new definition
-    #
-    proc ::foo args {;}
-    
-    nx::Object create o
-    ? {::o public object method BAR {} {;}} ::o::BAR
-    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
-
-    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
-    ? {info commands ::o::FOO} ""                    "a command ::o::FOO' does not exist"
-    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR exists"
-    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "define an object alias based on existing ::o::bar"
-    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "redefine an object alias based on alias based on existing ::o::FOO 87a2"
-}
-
-nx::test case alias-double-alias-redefine2 {
-    #
-    # same as alias-double-reference-define, but redefined twice instead of new definition
-    #
-    proc ::foo args {;}
-    
-    nx::Object create o
-    ? {::nsf::method::alias ::o FOO ::foo} ::o::FOO
-    ? {::o public object method BAR {} {;}} ::o::BAR
-    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
-
-    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
-    ? {info commands ::o::FOO} ::o::FOO              "a command ::o::FOO' exists"
-    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR exists"
-    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "redefine an object alias based on existing ::o::bar"
-    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "redefine an object alias based on alias based on existing ::o::FOO 87a2"
-}
-
-
-
-nx::test case alias-double-alias-object-method-redefine {
-
-    proc ::foo args {;}
-    
-    nx::Object create o
-    ? {::nsf::method::alias ::o FOO ::foo} ::o::FOO
-    ? {::o public object method bar {} {;}} ::o::bar
-
-    ? {info commands ::o::bar} ::o::bar              "handle ::o::bar exists"
-    ? {info commands ::o::FOO} ::o::FOO              "a command ::o::FOO' exists"
-    ? {info commands ::o::BAR} ""                    "a command ::o::BAR does not exist"
-    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "redefine an object alias based on existing (?) ::o::bar"
-    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "define an object alias based on alias based on existing ::o::FOO"
-    ? {info exists ::nsf::alias(::o,FOO,1)} 1
-    ? {info exists ::nsf::alias(::o,BAR,1)} 1
-    
-    o public object method bar {} {}
-    ? {info exists ::nsf::alias(::o,FOO,1)} 1
-    ? {info exists ::nsf::alias(::o,BAR,1)} 1
-}
-
-
-nx::test case alias-double-alias-object-method-redefine2 {
-
-    proc ::foo args {;}
-    
-    nx::Object create o
-    ? {::nsf::method::alias ::o FOO ::foo} ::o::FOO
-    ? {::o public object method BAR {} {;}} ::o::BAR
-    ? {::o public object method bar {} {;}} ::o::bar
-
-    ? {info commands ::o::bar} ::o::bar              "handle ::o::bar exists"
-    ? {info commands ::o::FOO} ::o::FOO              "a command ::o::FOO' exists"
-    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR does not exist"
-    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "redefine an object alias based on existing (?) ::o::bar"
-    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "redefine an object alias based on alias based on existing ::o::FOO 87a2"
-}
-
-
Index: tests/double-alias.test
===================================================================
diff -u -N
--- tests/double-alias.test	(revision 0)
+++ tests/double-alias.test	(revision 1d2bdbea2141f159f982e8dde0f9b0a6778a8b71)
@@ -0,0 +1,173 @@
+package prefer latest
+package require nx::test
+
+
+nx::test case alias-redefine-method1 {
+    #
+    # redefine an object method by an alias pointing to an alias
+    #
+    proc ::foo args {;}
+    
+    nx::Object create o
+    ? {::o public object method BAR {} {;}} ::o::BAR
+    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
+
+    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
+    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR exists"
+    ? {::nsf::method::alias o BAR ::o::bar} ::o::BAR "redefine an object method with an alias (pointing to an alias) 87a2"
+}
+
+nx::test case alias-redefine-method2 {
+    #
+    # redefine an object method by an alias pointing to an object method
+    #
+    proc ::foo args {;}
+    
+    nx::Object create o
+    ? {::o public object method BAR {} {;}} ::o::BAR
+    ? {::o public object method FOO {} {;}} ::o::FOO
+
+    ? {info commands ::o::FOO} ::o::FOO              "a command ::o::FOO exists"
+    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR exists"
+    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "redefine an object method with an alias (pointing to a method) 87a2"
+}
+
+
+nx::test case alias-double-alias-proc {
+
+    proc ::foo args {;}
+    nx::Object create o
+
+    ? {info commands ::o::FOO} ""                    "a command ::o::FOO' does not exist"
+    ? {info commands ::o::BAR} ""                    "a command ::o::BAR does not exist"
+    ? {::nsf::method::alias o FOO ::foo}    ::o::FOO "define an object alias based on existing ::foo"
+    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "define an object alias based on alias based on existing ::o::FOO"
+}
+
+nx::test case alias-double-alias-define {
+    #
+    # same as alias-double-reference-proc, but method instead of proc as target of o::FOO
+    #
+    proc ::foo args {;}
+
+    nx::Object create o
+    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
+
+    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
+    ? {info commands ::o::FOO} ""                    "a command ::o::FOO' does not exists"
+    ? {info commands ::o::BAR} ""                    "a command ::o::BAR does not exist"
+    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "define an object alias based on existing ::o::bar"
+    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "define an object alias based on alias based on existing (?) ::o::bar"
+}
+
+
+nx::test case alias-double-alias-redefine {
+    #
+    # same as alias-double-reference-define, but redefined instead of new definition
+    #
+    proc ::foo args {;}
+    
+    nx::Object create o
+    ? {::nsf::method::alias ::o FOO ::foo} ::o::FOO
+    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
+
+    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
+    ? {info commands ::o::FOO} ::o::FOO              "a command ::o::FOO' exists"
+    ? {info commands ::o::BAR} ""                    "a command ::o::BAR does not exist"
+    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "redefine an object alias based on existing ::o::bar"
+    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "define an object alias based on alias based on existing ::o::FOO"
+}
+
+nx::test case alias-double-alias-redefine0 {
+    #
+    # same as alias-double-reference-define, but redefined second cmd instead of new definition
+    #
+    proc ::foo args {;}
+    
+    nx::Object create o
+    ? {::o public object method BAR {} {;}} ::o::BAR
+    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
+
+    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
+    ? {info commands ::o::FOO} ""                    "a command ::o::FOO' does not exist"
+    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR exists"
+    ? {::nsf::method::alias o FOO ::foo} ::o::FOO    "define an object alias based on existing ::foo"
+    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "redefine an object alias based on alias based on existing ::o::FOO 87a2"
+}
+
+nx::test case alias-double-alias-redefine1 {
+    #
+    # same as alias-double-reference-define, but redefined second cmd instead of new definition
+    #
+    proc ::foo args {;}
+    
+    nx::Object create o
+    ? {::o public object method BAR {} {;}} ::o::BAR
+    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
+
+    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
+    ? {info commands ::o::FOO} ""                    "a command ::o::FOO' does not exist"
+    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR exists"
+    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "define an object alias based on existing ::o::bar"
+    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "redefine an object alias based on alias based on existing ::o::FOO 87a2"
+}
+
+nx::test case alias-double-alias-redefine2 {
+    #
+    # same as alias-double-reference-define, but redefined twice instead of new definition
+    #
+    proc ::foo args {;}
+    
+    nx::Object create o
+    ? {::nsf::method::alias ::o FOO ::foo} ::o::FOO
+    ? {::o public object method BAR {} {;}} ::o::BAR
+    ? {::nsf::method::alias ::o bar ::foo} ::o::bar
+
+    ? {info commands ::o::bar} ::o::bar              "::o::bar exists"
+    ? {info commands ::o::FOO} ::o::FOO              "a command ::o::FOO' exists"
+    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR exists"
+    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "redefine an object alias based on existing ::o::bar"
+    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "redefine an object alias based on alias based on existing ::o::FOO 87a2"
+}
+
+
+
+nx::test case alias-double-alias-object-method-redefine {
+
+    proc ::foo args {;}
+    
+    nx::Object create o
+    ? {::nsf::method::alias ::o FOO ::foo} ::o::FOO
+    ? {::o public object method bar {} {;}} ::o::bar
+
+    ? {info commands ::o::bar} ::o::bar              "handle ::o::bar exists"
+    ? {info commands ::o::FOO} ::o::FOO              "a command ::o::FOO' exists"
+    ? {info commands ::o::BAR} ""                    "a command ::o::BAR does not exist"
+    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "redefine an object alias based on existing (?) ::o::bar"
+    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "define an object alias based on alias based on existing ::o::FOO"
+    ? {info exists ::nsf::alias(::o,FOO,1)} 1
+    ? {info exists ::nsf::alias(::o,BAR,1)} 1
+    
+    o public object method bar {} {}
+    ? {info exists ::nsf::alias(::o,FOO,1)} 1
+    ? {info exists ::nsf::alias(::o,BAR,1)} 1
+}
+
+
+nx::test case alias-double-alias-object-method-redefine2 {
+
+    proc ::foo args {;}
+    
+    nx::Object create o
+    ? {::nsf::method::alias ::o FOO ::foo} ::o::FOO
+    ? {::o public object method BAR {} {;}} ::o::BAR
+    ? {::o public object method bar {} {;}} ::o::bar
+
+    ? {info commands ::o::bar} ::o::bar              "handle ::o::bar exists"
+    ? {info commands ::o::FOO} ::o::FOO              "a command ::o::FOO' exists"
+    ? {info commands ::o::BAR} ::o::BAR              "a command ::o::BAR does not exist"
+    ? {::nsf::method::alias o FOO ::o::bar} ::o::FOO "redefine an object alias based on existing (?) ::o::bar"
+    ? {::nsf::method::alias o BAR ::o::FOO} ::o::BAR "redefine an object alias based on alias based on existing ::o::FOO 87a2"
+}
+
+
Index: tests/forward.test
===================================================================
diff -u -N -r5ab2ad98d7e3d8509a26ea32ec64fa9cc78af2f8 -r1d2bdbea2141f159f982e8dde0f9b0a6778a8b71
--- tests/forward.test	(.../forward.test)	(revision 5ab2ad98d7e3d8509a26ea32ec64fa9cc78af2f8)
+++ tests/forward.test	(.../forward.test)	(revision 1d2bdbea2141f159f982e8dde0f9b0a6778a8b71)
@@ -2,6 +2,8 @@
 package require nx
 package require nx::test
 
+set ::tcl86 [package vsatisfies [package req Tcl] 8.6]
+
 ###########################################
 # trivial object delegation
 ###########################################
@@ -271,7 +273,11 @@
   ? {obj info object methods foo} ""
   obj public object forward ::ns1::foo
   ? {obj info object methods foo} "foo"
-  ? {obj foo X} {TCL LOOKUP COMMAND ::ns1::foo} "invalid target command"
+  if {$::tcl86} {
+    ? {obj foo X} {TCL LOOKUP COMMAND ::ns1::foo} "invalid target command"
+  } else {
+    ? {obj foo X} {invalid command name "::ns1::foo"} "invalid target command"
+  }
   namespace eval ::ns1 {proc foo {p} {return $p}}
   ? {obj foo X} "X"
   obj public object forward ::ns1::foo %method %method
@@ -354,7 +360,11 @@
   ? {obj foo 1 2 3} [list 1 2 3 %]
 
   obj public object forward foo list {%obj foo}
-  ? {obj foo 1 2 3} "TCL LIMIT STACK" "stack overflow"
+  if {$::tcl86} {
+    ? {obj foo 1 2 3} "TCL LIMIT STACK" "stack overflow"
+  } else {
+    ? {obj foo 1 2 3} {too many nested evaluations (infinite loop?)} "stack overflow"
+  }
 
   obj public object forward foo list {%apply {{x} {return $x}} A}
   ? {obj foo 1 2 3} [list A 1 2 3]
@@ -376,7 +386,11 @@
   ##
 
   obj public object forward foo list {%@end %::proc}
-  ? {obj foo 1 2 3} {TCL WRONGARGS} "provided wrong arguments for target command"
+  if {$::tcl86} {
+    ? {obj foo 1 2 3} {TCL WRONGARGS} "provided wrong arguments for target command"
+  } else {
+    ? {obj foo 1 2 3} {wrong # args: should be "::proc name args body"} "provided wrong arguments for target command"
+  }
 
   # the next test does not work unless called from nxsh, which imports ::nx::self
   # obj public object forward foo list {%@end %::self}
@@ -386,14 +400,22 @@
   ? {obj foo 1 2 3} [list 1 2 3 ::obj] "fully qualified self"
 
   obj public object forward foo list {%@end %::1}
-  ? {obj foo 1 2 3} {TCL LOOKUP COMMAND ::1} "forward to non-existing object"
+  if {$::tcl86} {
+    ? {obj foo 1 2 3} {TCL LOOKUP COMMAND ::1} "forward to non-existing object"
+  } else {
+    ? {obj foo 1 2 3} {invalid command name "::1"} "forward to non-existing object"
+  }
 
   ##
   ## position prefixes are interpreted in a context-dependent manner:
   ##
 
   obj public object forward foo list {%@1 %@1}
-  ? {obj foo 1 2 3} {TCL LOOKUP COMMAND @1}  "forward to non-existing cmd"
+  if {$::tcl86} {
+    ? {obj foo 1 2 3} {TCL LOOKUP COMMAND @1}  "forward to non-existing cmd"
+  } else {
+    ? {obj foo 1 2 3} {invalid command name "@1"}  "forward to non-existing cmd"
+  }
 
   if {![string length "ISSUES"]} {
 
Index: tests/info-variable.test
===================================================================
diff -u -N -r2f921800dfd3c92bfa176f9d00f366bfc9341da1 -r1d2bdbea2141f159f982e8dde0f9b0a6778a8b71
--- tests/info-variable.test	(.../info-variable.test)	(revision 2f921800dfd3c92bfa176f9d00f366bfc9341da1)
+++ tests/info-variable.test	(.../info-variable.test)	(revision 1d2bdbea2141f159f982e8dde0f9b0a6778a8b71)
@@ -52,9 +52,9 @@
   #? {Person info parameter syntax -force:switch} "?-force?"
   #? {Person info parameter name "a b"} "a"
 
-  set emsg [string cat \
-                "wrong # of elements in parameter definition. " \
-                "Should be a list of 1 or 2 elements, but got: ''"]
+  set emsg [join [list \
+                      "wrong # of elements in parameter definition. " \
+                      "Should be a list of 1 or 2 elements, but got: ''"] ""]
 
   foreach subcmd {default syntax type list name} {
     ? [list nsf::parameter::info $subcmd ""] $emsg
Index: tests/shells.test
===================================================================
diff -u -N -r4a0eb5eeae386136555d77c233ad9f4a971d71f4 -r1d2bdbea2141f159f982e8dde0f9b0a6778a8b71
--- tests/shells.test	(.../shells.test)	(revision 4a0eb5eeae386136555d77c233ad9f4a971d71f4)
+++ tests/shells.test	(.../shells.test)	(revision 1d2bdbea2141f159f982e8dde0f9b0a6778a8b71)
@@ -87,7 +87,7 @@
   ? [list exec $nxsh -c << "catch {nx::Object eval {exit 1}}"] "child process exited abnormally"
 
   # just 8.6 or newer
-  if {[info command try] eq ""} return
+  if {[info command yield] eq ""} return
   ? [list exec $nxsh -c << [list nx::Object eval {try { exit 6 } \
                                                       on break {} {;} \
                                                       on return {} {;} \
Index: tests/submethods.test
===================================================================
diff -u -N -r96e318fb438fdc1bd75b09307fdb535cc93f6323 -r1d2bdbea2141f159f982e8dde0f9b0a6778a8b71
--- tests/submethods.test	(.../submethods.test)	(revision 96e318fb438fdc1bd75b09307fdb535cc93f6323)
+++ tests/submethods.test	(.../submethods.test)	(revision 1d2bdbea2141f159f982e8dde0f9b0a6778a8b71)
@@ -945,21 +945,21 @@
 
 nx::test case ensemble-forwards {
   set C [nx::Class new {
-    set handle [:forward "foo 1" string cat %method]
+    set handle [:forward "foo 1" join %method ""]
     ? [list info commands $handle] $handle
-    set handle [:public forward "foo 2" string cat %method]
+    set handle [:public forward "foo 2" join %method ""]
     ? [list info commands $handle] $handle
-    set handle [:protected forward "foo 3" string cat %method]
+    set handle [:protected forward "foo 3" join %method ""]
     ? [list info commands $handle] $handle
-    set handle [:private forward "foo 4" string cat %method]
+    set handle [:private forward "foo 4" join %method ""]
     ? [list info commands $handle] $handle
-    set handle [:object forward "foo 5" string cat %method]
+    set handle [:object forward "foo 5" join %method ""]
     ? [list info commands $handle] $handle
-    set handle [:public object forward "foo 6" string cat %method]
+    set handle [:public object forward "foo 6" join %method ""]
     ? [list info commands $handle] $handle
-    set handle [:protected object forward "foo 7" string cat %method]
+    set handle [:protected object forward "foo 7" join %method ""]
     ? [list info commands $handle] $handle
-    set handle [:private object forward "foo 8" string cat %method]
+    set handle [:private object forward "foo 8" join %method ""]
     ? [list info commands $handle] $handle
   }]