out_of_range error

[ChristopheVuillot]

Hello,

trying to run on a very simple circuit fails for me with the following error:

terminate called after throwing an instance of 'std::out_of_range'
what(): vector::_M_range_check: __n (which is 0) >= this->size() (which is 0)
Aborted (core dumped)

I'm running the command:
./bazel-bin/src/tesseract --circuit circuit_simple.stim --sample-num-shots 100 --print-stats

the file circuit_simple.stim contains:

RX 0
Z_ERROR(0.01) 0
MX 0
DETECTOR rec[-1]
MX 0
DETECTOR rec[-1]
OBSERVABLE_INCLUDE(0) rec[-1]

I'm on linux ubuntu and compiled with bazel 8.1.1:
bazel build src:all

One issue I had during compilation is that it didn't recognize the option 'mmacosx-version-min=10.15' so I commented the corresponding line in src/BUILD. The diff of what I did is:

@@ -26,8 +26,8 @@ OPT_COPTS = select({
         "-Ofast",
         "-fno-fast-math",
         "-flto",
-        "-march=native",
-        "-mmacosx-version-min=10.15"
+        "-march=native"#,
+#        "-mmacosx-version-min=10.15"
     ],
     ":debug": ["-Og"],
 }) + ["-std=c++20"]

[noajshu]

Tesseract currently requires XY coordinates for all qubits. We should be able to remove this requirement in a future release.

For now, could you try adding qubit coordinates and see if that is causing the exception?

[ChristopheVuillot]

Thanks for looking at it!
Adding coordinate here do not seem to fix the problem. The stim file now contains:

QUBIT_COORDS(0, 0) 0
RX 0
Z_ERROR(0.01) 0
MX 0
DETECTOR rec[-1]
MX 0
DETECTOR rec[-1]
OBSERVABLE_INCLUDE(0) rec[-1]

I get exactly the same error with it.

[noajshu]

Hi Cristophe,

Could you try again with the flag --det-order-bfs? This should fix the problem.

[ChristopheVuillot]

Yes it is fixed thanks!