Simple code causes a read error: cannot access memory at

Question

I am trying to use gdb with python support MinGW-builds . And I ran into an error. This is pretty simple code, and it works great when debugging in MSVC.

D:\CppProject\c1\bin\Debug>gdb c1.exe GNU gdb (GDB) 7.6 (copyright, license, bug report, etc omitted here) Reading symbols from D:\CppProject\c1\bin\Debug\c1.exe...done. (gdb) l 1 #include <iostream> 2 #include <vector> 3 4 using namespace std; 5 6 int main() 7 { 8 vector<string> v; 9 v.push_back("first"); 10 v.push_back("second"); (gdb) 11 cout<<v[0]<<endl; 12 cout<<v[1]<<endl; 13 14 return 0; 15 } (gdb) break 11 Breakpoint 1 at 0x4016c9: file D:\CppProject\c1\main.cpp, line 11. (gdb) run Starting program: D:\CppProject\c1\bin\Debug\c1.exe [New Thread 1256.0xbe8] Breakpoint 1, main () at D:\CppProject\c1\main.cpp:11 11 cout<<v[0]<<endl; (gdb) pv $1 = std::vector of length 2, capacity 2 = {"first", "second"} (gdb) pv[0] $2 = <error reading variable: Cannot access memory at address 0x29a2ca50> 

Answer 1

This may seem basic - did you compile with -O0? I suspect that optimizing the compiler may cause problems.