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I've never had any trouble debugging Nim, which compiles to C. The Nim compiler adds #line directives so you can just use gdb/lldb[1]. Can you elaborate on what

• qznc 9y ago
  Does Nim optimize anything on the way to C? That usually destroys useful information. I can give you an example from C compilers. Consider a simple loop: int a[] = ...; for (int i=0; i<max; i++) { print(a[i]); } Something fishy is printed, so I run it in my debugger, break at some point, and print "i". Gdb can usually do that. Now think about the optimizations a compiler probably did: While the index is incremented by 1, we actually step 4 bytes further due to the int array, so the compiler does i+=4 instead to avoid the multiply by 4 instruction. While i starts at 0, we can instead use the "a" pointer and avoid to add an offset at every loop iteration. The code might actually look like this: int *a = ... int end = a + max*4; for (char* x=a; x < end; x+=4) { print(x); } How can gdb print "i"? The trick is DWARF [0], basically the compiler inserts the information: If you want to print i here, then compute it by i=(x-a)/4. tldr: #line directives are not enough [0] https://en.wikipedia.org/wiki/DWARF https://en.wikipedia.org/wiki/DWARF