Gradients example doesn't make progress on the GPU runners #622
Description
Required prerequisites
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Describe the bug
Enabling a basic validation that runs all examples on the GPU backends, the gradients example fails to make progress. Locally, everything works fine, but on the runners the values are odd:
Locally:
Optimize with no gradients.
<H>(0.000000, 0.000000) = -0.436286
<H>(1.570796, 0.000000) = 12.250291
<H>(0.000000, 1.570796) = 9.407001
<H>(-1.241051, -0.962909) = 8.691541
<H>(-0.620525, -0.481455) = 6.446059
...
On the GH runner:
Optimize with no gradients.
<H>(0.000000, 0.000000) = 15.532000
<H>(1.570796, 0.000000) = 15.532000
<H>(0.000000, 1.570796) = 15.532000
<H>(0.107242, 0.000000) = 15.532000
<H>(0.000000, 0.082867) = 15.532000
...
<H>(0.000000, 0.000000) = 15.532000
<H>(0.000000, 0.000000) = 15.532000 (keeps being this)
I haven't had a chance to look further.
May be related:
#583
#623
#399
Steps to reproduce the bug
In .github/workflows/publishing.yml enable the /home/cudaq/examples/cpp/other/gradients.cpp example in the validation job, then manually run the workflow for a recent deployment. It would be good to find a local repro, but I don't have one right now.
Expected behavior
The example should succeed.
Is this a regression? If it is, put the last known working version (or commit) here.
Not a regression
Environment
- CUDA Quantum version: latest main
- Python version: N/A
- C++ compiler: any
- Operating system: N/A
Suggestions
No response