OK, the problem is that make_frame fails to put the arguments into the frame.

I do not (yet) know why not, but that is the problem.

src/c/environment/environment.c

@@ -52,6 +52,7 @@ struct pso_pointer initialise_environment( uint32_t node ) {
             object->payload.cons.cdr = nil;
 
             nil = n;
+            lock_object( nil);
             debug_print( L"success\n", DEBUG_BOOTSTRAP, 0);
         } else {
             result =
@@ -72,6 +73,7 @@ struct pso_pointer initialise_environment( uint32_t node ) {
             object->payload.cons.cdr = t;
 
             t = n;
+            lock_object(t);
             debug_print( L"success\n", DEBUG_BOOTSTRAP, 0);
         } else {
             result =
@@ -86,6 +88,7 @@ struct pso_pointer initialise_environment( uint32_t node ) {
         result = c_bind( c_string_to_lisp_symbol( L"t" ), t, result );
 
         environment_initialised = true;
+        debug_print( L"\nEnvironment initialised successfully.\n", DEBUG_BOOTSTRAP, 0);
     }
 
     return result;

src/c/memory/node.c

@@ -41,9 +41,10 @@ struct pso_pointer nil = ( struct pso_pointer ) { 0, 0, 0 };
 
 /**
  * @brief the canonical `t` (true) pointer.
- *
+ * Offset 4, because `t` should be the second pso2 allocated, the offset is
+ * given in words, and the size of a pso2 should be four words.
  */
-struct pso_pointer t = ( struct pso_pointer ) { 0, 0, 1 };
+struct pso_pointer t = ( struct pso_pointer ) { 0, 0, 4 };
 
 
 /**

src/c/memory/page.c

@@ -287,7 +287,7 @@ struct pso_pointer allocate_page( uint8_t size_class ) {
                 memset( pg, 0, sizeof( union page ) );
                 pages[npages_allocated] = pg;
                 debug_printf( DEBUG_ALLOC, 0,
-                              L"Allocated page %d for objects of size class %x.\n",
+                              L"\nAllocated page %d for objects of size class %x.\n",
                               npages_allocated, size_class );
 
                 freelists[size_class] =

src/c/memory/pso.c

@@ -15,6 +15,7 @@
  */
 
 #include <stdbool.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include "debug.h"
@@ -38,7 +39,8 @@
   * @return struct pso_pointer a pointer to the newly allocated object
   */
 struct pso_pointer allocate( char *tag, uint8_t size_class ) {
-    struct pso_pointer result = nil;
+	// `t`, because if `allocate_page` fails it will be set to `nil`.
+    struct pso_pointer result = t;
 
 #ifdef DEBUG
     debug_printf( DEBUG_ALLOC, 0, L"Allocating object of size class %d with tag `%s`... ", size_class, tag);
@@ -49,7 +51,14 @@ struct pso_pointer allocate( char *tag, uint8_t size_class ) {
             result = allocate_page( size_class );
         }
 
-        if ( !exceptionp( result ) ) {
+        if (nilp(result)) {
+        	fputws( L"FATAL: Page space exhausted\n", stderr );
+        	exit(1); // TODO: we don't want to do this! Somehow, we need to
+        	// recover a workable environment, ideally by throwing a pre-made
+        	// exception.
+        }
+
+        if ( !exceptionp( result ) && !nilp(result)) {
             result = freelists[size_class];
             struct pso2 *object = pointer_to_object( result );
             freelists[size_class] = object->payload.free.next;
@@ -69,7 +78,6 @@ struct pso_pointer allocate( char *tag, uint8_t size_class ) {
             if ( object->header.count != 0 ) {
                 // TODO: return an exception instead? Or warn, set it, and continue?
             }
-
         }
     }                           // TODO: else throw exception
 

src/c/ops/string_ops.c

@@ -127,7 +127,7 @@ struct pso_pointer make_keyword( wint_t c, struct pso_pointer tail ) {
  * @param tail the symbol which is being built.
  */
 struct pso_pointer make_symbol( wint_t c, struct pso_pointer tail ) {
-    return make_string_like_thing( c, tail, STRINGTAG );
+    return make_string_like_thing( c, tail, SYMBOLTAG );
 }
 
 

src/c/ops/truth.c

@@ -49,12 +49,15 @@ bool not( struct pso_pointer p ) {
  * each is considered equivalent. So we don't check the node when considering
  * whether `nil` really is `nil`, or `t` really is `t`.
  * 
+ * Note that the offset is 4 because `t` should be the second pso2 allocated,
+ * the offset is given in words, and the size of a pso2 should be four words
+ *
  * @param p a pointer
  * @return true if `p` points to `t`.
  * @return false otherwise.
  */
 bool truep( struct pso_pointer p ) {
-    return ( p.page == 0 && p.offset == 1 );
+    return ( p.page == 0 && p.offset == 4 );
 }
 
 /**