diff --git a/.buildbot.sh b/.buildbot.sh
index 3d42111..4d9d2dd 100644
--- a/.buildbot.sh
+++ b/.buildbot.sh
@@ -31,23 +31,4 @@ cd ..
 export YK_BUILD_TYPE=debug
 make -j `nproc`
 
-cd tests
-# YKFIXME: The JIT can't yet run the test suite, but the following commented
-# commands are what we are aiming at having work.
-#
-# ../src/lua -e"_U=true" all.lua
-# YKD_SERIALISE_COMPILATION=1 ../src/lua -e"_U=true" all.lua
-#
-# (Adding `YKD_SERIALISE_COMPILATION` exercises different threading behaviour
-# that could help to shake out more bugs)
-#
-# Until we can run `all.lua` reliably, we just run the tests that we know to
-# run within reasonable time).
-LUA=../src/lua
-for serialise in 0 1; do
-    for test in api bwcoercion closure code events \
-        gengc pm tpack tracegc vararg goto cstack locals; do
-        echo "### YKD_SERIALISE_COMPILATION=$serialise $test.lua ###"
-        YKD_SERIALISE_COMPILATION=$serialise ${LUA} -e"_U=true" ${test}.lua
-    done
-done
+sh test.sh
diff --git a/README.md b/README.md
index 25b00b1..56bc80a 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,15 @@ cd tests # navigate to tests directory
 
 ```shell
 run_docker_ci_job # local path to https://github.com/softdevteam/buildbot_config/blob/master/bin/run_docker_ci_job
+
+```
+## Debugging
+
+Use `LYK_VERBOSE` environment variable to print LYK (lua yk) debug logs:
+```shell
+LYK_VERBOSE=1 gdb --batch -ex 'r' -ex 'bt' --args ../src/lua all.lua 
+LYK_VERBOSE=1 ../src/lua all.lua 
+LYK_VERBOSE=1 sh ./test.sh
 ```
 
 ### State of Tests
diff --git a/src/Makefile b/src/Makefile
index fd864b4..898a013 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -21,7 +21,8 @@ SYSCFLAGS=
 SYSLDFLAGS=
 SYSLIBS=
 
-MYCFLAGS=
+# YKFIXME: LYK_DEBUG is a debug flag for the Yk integration. Once YkLua is stable we can remove it.
+MYCFLAGS=-DLYK_DEBUG
 MYLDFLAGS=
 MYLIBS=
 MYOBJS=
diff --git a/src/lcode.c b/src/lcode.c
index ceb135a..96f0c45 100644
--- a/src/lcode.c
+++ b/src/lcode.c
@@ -391,7 +391,7 @@ int luaK_code (FuncState *fs, Instruction i) {
                   MAX_INT, "opcodes");
   f->code[fs->pc++] = i;
 #ifdef USE_YK
-  yk_set_location(f, i, idx, fs->pc);
+  yk_ok_instruction_loaded(f, i, idx);
 #endif
   savelineinfo(fs, f, fs->ls->lastline);
   return idx;  /* index of new instruction */
diff --git a/src/lfunc.c b/src/lfunc.c
index d110c83..88df14a 100644
--- a/src/lfunc.c
+++ b/src/lfunc.c
@@ -251,7 +251,7 @@ Proto *luaF_newproto (lua_State *L) {
   f->sizep = 0;
   f->code = NULL;
 #ifdef USE_YK
-  f->yklocs = NULL;
+  yk_on_newproto(f);
 #endif
   f->sizecode = 0;
   f->lineinfo = NULL;
@@ -273,7 +273,7 @@ Proto *luaF_newproto (lua_State *L) {
 
 void luaF_freeproto (lua_State *L, Proto *f) {
 #ifdef USE_YK
-  yk_free_locactions(f);
+  yk_on_proto_free(f);
 #endif
   luaM_freearray(L, f->code, f->sizecode);
   luaM_freearray(L, f->p, f->sizep);
diff --git a/src/lobject.h b/src/lobject.h
index 3bda66d..642a8d9 100644
--- a/src/lobject.h
+++ b/src/lobject.h
@@ -556,7 +556,8 @@ typedef struct Proto {
   TValue *k;  /* constants used by the function */
   Instruction *code;  /* opcodes */
 #ifdef USE_YK
-  YkLocation *yklocs; /* JIT locations */
+  YkLocation **yklocs; /* JIT locations */
+  int yklocs_size;
 #endif
   struct Proto **p;  /* functions defined inside the function */
   Upvaldesc *upvalues;  /* upvalue information */
diff --git a/src/lundump.c b/src/lundump.c
index faa540b..dd990bd 100644
--- a/src/lundump.c
+++ b/src/lundump.c
@@ -267,7 +267,7 @@ static void loadFunction (LoadState *S, Proto *f, TString *psource) {
   f->maxstacksize = loadByte(S);
   loadCode(S, f);
   #ifdef USE_YK
-  yk_set_locations(f);
+  yk_on_proto_loaded(f);
   #endif
   loadConstants(S, f);
   loadUpvalues(S, f);
diff --git a/src/lyk.c b/src/lyk.c
index e901748..6ecebc1 100644
--- a/src/lyk.c
+++ b/src/lyk.c
@@ -6,75 +6,148 @@
 #include "ldebug.h"
 #include <stdlib.h>
 #include <yk.h>
-
-#define _DEFAULT_SOURCE /* for reallocarray() */
-
+#include "stdio.h"
 /*
  *  Function prototypes in Lua are loaded through two methods:
  *    1.  They are loaded from text source via the `luaY_parser`.
  *    2.  They can also be loaded from binary representation using `luaU_undump`, where
  *        prototypes are previously dumped and saved.
- * 
- *  Yk tracing locations are allocated using both of these methods 
+ *
+ *  Yk tracing locations are allocated using both of these methods
  *  using `yk_set_location` and `yk_set_locations` respectively.
-*/
+ */
+
+#ifdef LYK_DEBUG
+static int LYK_VERBOSE = -1;
+
+int is_verbose() {
+  if (LYK_VERBOSE == -1) {
+    LYK_VERBOSE = getenv("LYK_VERBOSE") != NULL;
+  }
+  return LYK_VERBOSE;
+}
+
+void print_proto_info(char *msg, Proto *f) {
+  if (!is_verbose()){
+    return;
+  }
+  char *source = NULL;
+  if (f->source != NULL) {
+    source = getstr(f->source);
+  }
+  char *vars = NULL;
+  if (f->locvars != NULL && f->locvars->varname != NULL) {
+    vars = getstr(f->locvars->varname);
+  }
+  printf("[LYK] %s. \t f:\t%p \t source: %s: \t vars: %s", msg, f, source, vars);
+  if (f->yklocs != NULL) {
+    printf("\t sizecode: %d", f->sizecode);
+  }
+  printf("\n");
+}
+#endif // LYK_DEBUG
+
+void yk_on_newproto(Proto *f) {
+  #ifdef LYK_DEBUG
+  if (is_verbose()) {
+    printf("[LYK] yk_new_proto %p\n", f);
+  }
+  #endif // LYK_DEBUG
+  f->yklocs = NULL;
+}
 
 /*
  *  Is the instruction `i` the start of a loop?
  *
- *  YKFIXME: Numeric and Generic loops can be identified by `OP_FORLOOP` and `OP_TFORLOOP` opcodes. 
- *  Other loops like while and repeat-until are harder to identify since they are based on 
+ *  YKFIXME: Numeric and Generic loops can be identified by `OP_FORLOOP` and `OP_TFORLOOP` opcodes.
+ *  Other loops like while and repeat-until are harder to identify since they are based on
  *  `OP_JMP` instruction.
  */
 int is_loop_start(Instruction i) {
   return (GET_OPCODE(i) == OP_FORLOOP || GET_OPCODE(i) == OP_TFORLOOP);
 }
 
-inline YkLocation *yk_lookup_ykloc(CallInfo *ci, Instruction *pc){
+inline YkLocation *yk_lookup_ykloc(CallInfo *ci, Instruction *pc) {
   YkLocation *ykloc = NULL;
   lua_assert(isLua(ci));
   Proto *p = ci_func(ci)->p;
   lua_assert(p->code <= pc && pc <= p->code + p->sizecode);
   if (is_loop_start(*pc)) {
-    ykloc = &p->yklocs[pc - p->code];
+    ykloc = p->yklocs[pc - p->code];
   }
   return ykloc;
 }
 
-inline void yk_set_location(Proto *f, Instruction i, int idx, int pc) {
-  // YKOPT: Reallocating for every instruction is inefficient.
-  f->yklocs = reallocarray(f->yklocs, pc, sizeof(YkLocation));
-  lua_assert(f->yklocs != NULL && "Expected yklocs to be defined!");
-  if (is_loop_start(i))
-  {
-    f->yklocs[idx] = yk_location_new();
+void set_location(Proto *f, int i) {
+  YkLocation *loc = (YkLocation *)malloc(sizeof(YkLocation));
+  lua_assert(loc != NULL && "Expected loc to be defined!");
+  *loc = yk_location_new();
+  f->yklocs[i] = loc;
+  #ifdef LYK_DEBUG
+  if (is_verbose()){
+    printf("[LYK] yk_location_new. %p->yklocs[%d]=%p\n", f, i, loc);
   }
+  #endif // LYK_DEBUG
 }
 
-inline void yk_set_locations(Proto *f) {
-  f->yklocs = calloc(f->sizecode, sizeof(YkLocation));
-  lua_assert(f->yklocs != NULL && "Expected yklocs to be defined!");
-  for (int i = 0; i < f->sizecode; i++){
-     if (is_loop_start(i)){
-      f->yklocs[i] = yk_location_new();
+inline void yk_ok_instruction_loaded(Proto *f, Instruction i, int idx) {
+  // YKOPT: Reallocating for every instruction is inefficient.
+  YkLocation **new_locations = calloc(f->sizecode, sizeof(YkLocation *));
+  lua_assert(new_locations != NULL && "Expected yklocs to be defined!");
+  
+  // copy previous locations over
+  if (f->yklocs != NULL) {
+    for (int i = 0; i < f->yklocs_size; i++) {
+      if (f->yklocs[i] != NULL) {
+        new_locations[i] = f->yklocs[i];
+      }
+      else {
+        new_locations[i] = NULL;
+      }
     }
+    free(f->yklocs);
   }
+  f->yklocs = new_locations;
+  f->yklocs_size = f->sizecode;
+  #ifdef LYK_DEBUG
+  if (is_loop_start(i)) {
+    set_location(f, idx);
+  }
+  #endif // LYK_DEBUG
 }
 
-void free_loc(Proto *f, Instruction i, int idx) {
-  if (is_loop_start(i)) {
-    yk_location_drop(f->yklocs[idx]);
+inline void yk_on_proto_loaded(Proto *f) {
+  #ifdef LYK_DEBUG
+  print_proto_info("yk_set_locations", f);
+  #endif // LYK_DEBUG
+  f->yklocs = calloc(f->sizecode, sizeof(YkLocation *));
+  lua_assert(f->yklocs != NULL && "Expected yklocs to be defined!");
+  f->yklocs_size = f->sizecode;
+  for (int i = 0; i < f->sizecode; i++) {
+    if (is_loop_start(i)) {
+      set_location(f, i);
+    }
   }
 }
 
-inline void yk_free_locactions(Proto *f) {
-  // YK locations are initialised as close as possible to the function loading, 
+inline void yk_on_proto_free(Proto *f) {
+  // YK locations are initialised as close as possible to the function loading,
   // However, this load can fail before we initialise `yklocs`.
   // This NULL check is a workaround for that.
-  if (f->yklocs != NULL) {
+  if (f->yklocs != NULL)  {
     for (int i = 0; i < f->sizecode; i++) {
-      free_loc(f, f->code[i], i);
+      YkLocation *loc = f->yklocs[i];
+      if (loc != NULL) {
+        #ifdef LYK_DEBUG
+        if (is_verbose()){
+          printf("[LYK] yk_location_drop. %p->yklocs[%d]=%p\n", f, i, loc);
+        }
+        #endif // LYK_DEBUG
+        yk_location_drop(*loc);
+        free(loc);
+      }
     }
+
     free(f->yklocs);
     f->yklocs = NULL;
   }
diff --git a/src/lyk.h b/src/lyk.h
index 5e10992..3f6523b 100644
--- a/src/lyk.h
+++ b/src/lyk.h
@@ -5,11 +5,13 @@
 #include "lopcodes.h"
 #include "lstate.h"
 
-void yk_set_location(Proto *f, Instruction i, int idx, int pc);
+void yk_on_newproto(Proto *f);
 
-void yk_set_locations(Proto *f);
+void yk_ok_instruction_loaded(Proto *f, Instruction i, int idx);
 
-void yk_free_locactions(Proto *f);
+void yk_on_proto_loaded(Proto *f);
+
+void yk_on_proto_free(Proto *f);
 
 YkLocation* yk_lookup_ykloc(CallInfo *ci, Instruction *pc);
 
diff --git a/test.sh b/test.sh
new file mode 100644
index 0000000..3ba710c
--- /dev/null
+++ b/test.sh
@@ -0,0 +1,29 @@
+#!/bin/sh
+
+set -e
+
+cd tests
+
+# YKFIXME: The JIT can't yet run the test suite, but the following commented
+# commands are what we are aiming at having work.
+#
+# ../src/lua -e"_U=true" all.lua
+# YKD_SERIALISE_COMPILATION=1 ../src/lua -e"_U=true" all.lua
+#
+# (Adding `YKD_SERIALISE_COMPILATION` exercises different threading behaviour
+# that could help to shake out more bugs)
+#
+# Until we can run `all.lua` reliably, we just run the tests that we know to
+# run within reasonable time).
+
+LUA=../src/lua
+
+# Non-serialised compilation tests
+# YKFIXME: The following tests are known to work with non-serialised JIT
+for test in api bwcoercion closure code events \
+    gengc pm tpack tracegc vararg goto cstack locals; do
+    YKD_SERIALISE_COMPILATION=0 ${LUA} -e"_U=true" ${test}.lua
+done
+
+# Serialised compilation tests
+YKD_SERIALISE_COMPILATION=1 ${LUA} -e"_U=true" all.lua