[Parser] free(): double free detected in tcache 2

[wesuRage]

$  ./src/frontend/parser/parser_test examples/a.glx 
Lexical Analysis:
-----------------
Line 1, Column 1-4: TYPE INTEGER "int"
Line 1, Column 5-7: IDENTIFIER "oi"
Line 1, Column 8-10: ASSIGN ":="
Line 1, Column 10-11: NUMBER "3"
Line 1, Column 11-12: SEMICOLON ";"
Line 1, Column 12-12: END OF FILE "EOF"

Parsing:
-----------------
AST:
Node Type: Program
  Program has 1 statements
  Node Type: Variable Declaration
    Variable Name: oi
    Is Pointer: false
    Is Constant: false
    Type: int
    Value:
      Node Type: Numeric Literal
        Value: 3.000000
free(): double free detected in tcache 2
Aborted (core dumped)

running the backtrace on gdb:

Program received signal SIGABRT, Aborted.
__pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at ./nptl/pthread_kill.c:44
warning: 44     ./nptl/pthread_kill.c: No such file or directory
(gdb) backtrace
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at ./nptl/pthread_kill.c:44
#1  0x00007ffff7e44ebf in __pthread_kill_internal (threadid=<optimized out>, signo=6) at ./nptl/pthread_kill.c:78
#2  0x00007ffff7df0c82 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007ffff7dd94f0 in __GI_abort () at ./stdlib/abort.c:79
#4  0x00007ffff7dda32d in __libc_message_impl (fmt=fmt@entry=0x7ffff7f5c303 "%s\n") at ../sysdeps/posix/libc_fatal.c:132
#5  0x00007ffff7e4e9e5 in malloc_printerr (str=str@entry=0x7ffff7f5f6a8 "free(): double free detected in tcache 2") at ./malloc/malloc.c:5772
#6  0x00007ffff7e50e59 in _int_free (av=0x7ffff7f98ac0 <main_arena>, p=<optimized out>, have_lock=have_lock@entry=0) at ./malloc/malloc.c:4541
#7  0x00007ffff7e534ff in __GI___libc_free (mem=<optimized out>) at ./malloc/malloc.c:3398
#8  0x000055555555e2f5 in freeTokens (tokens=0x555555565bd0, tokenCount=6) at /root/C/galaxy/src/frontend/freeTokens.c:19
#9  0x00005555555554e5 in main (argc=2, argv=0x7fffffffda68) at /root/C/galaxy/src/frontend/parser/parser.test.c:59
(gdb) 

as said on gdb, the line 19 of freeTokens.c is: free(tokens[i].lexeme);