Segmentation Fault

[chMoussa]

Hello,

I have a segmentation fault from getMeasurementStrings and getMeasurementCounts.
I installed XACC and plugings with pip on Docker images.
I am attaching the printing of a simple script and the script.

import pyxacc as xacc
import sys

def hello(acc="ibm",backendinput="ibmq_qasm_simulator"):
xacc.Initialize(["--compiler","quil"])
accelerator = acc
backend = backendinput

qpu = xacc.getAccelerator(accelerator)
nqbits = 2

xacc.setOption(acc+"-backend",backend)
# code commented is for setting
# the number of trials one run the circuit (default 1024)
# One can set any option that come with the accelerator
# xacc.setOption("ibm-shots","1024")
# xacc.setOption("rigetti-trial","1024")

qreg = qpu.createBuffer("qreg",nqbits)

src = """__qpu__ bell(AcceleratorBuffer b){
H 0
CNOT 0 1
MEASURE 0 [0]
MEASURE 1 [1]
}
"""

program = xacc.Program(qpu,src)
program.build()

k = program.getKernel("bell")
k.execute(qreg,[])

print(qreg.getMeasurementStrings())
print(qreg.getMeasurementCounts())
xacc.Finalize()

if name == "main":

if len(sys.argv) == 3:
    hello(sys.argv[1],sys.argv[2])
else:
    hello()

[amccaskey]

@chMoussa Thanks for filing this issue. We're going to look into it today and see what we find. It may be that the Pip wheels need to be updated.

[czhao39]

@chMoussa Your code ran successfully for me. I built XACC and the plugins from source, though, so I will try using pip and get back to you in a bit.

[czhao39]

@chMoussa The xacc-ibm code currently on PyPI is outdated. We tried pip installing the latest version of the xacc-ibm plugin and your program worked, so we'll release the updated version to PyPI soon. Once we do that, you can run pip install -U xacc-ibm to upgrade.

[amccaskey]

@chMoussa I have uploaded an updated xacc-ibm wheel to PyPi. You can now run

$ python -m pip install --upgrade xacc-ibm

Let us know if that gets rid of your bug.

Note you should see it upgrade to version 0.1.1

[chMoussa]

What is the new name?

[amccaskey]

Hey Charles,

Notice that you don't have the IBM plugin installed (does not say 'Installed plugin 'xacc-ibm-'). Also notice that your XACC install is in your ~/.local/ directory, so you installed the XACC wheel with --user. If you run pip install xacc --user, then you must run all plugin installs with --user.

I suggest

$ python -m pip uninstall xacc-ibm (which should remove it from wherever it was installed)
$ python -m pip install xacc-ibm --user --no-cache

You should see that it downloads and install version 0.1.1.

[chMoussa]

I run the pip upgrade and it told me it was upgraded to 0.1.1.
But anyway I run your last commands and I finally got rid of the segmentation fault.

[chMoussa]

Can we do the same for rigetti ?

[amccaskey]

Hey @chMoussa I have updated the rigetti wheels as well. Go ahead and try to uninstall what you have and then run

$ python -m pip install xacc-rigetti --no-cache --user

Only pass --user if that is what you passed for XACC.

Note the version that you should see for rigetti is 0.1.3

[chMoussa]

Working well now thanks