Repository: spyder-ide/spyder

Issue:
`local variable 'channel_url' referenced before assignment` error when checking for updates
## Description

### What steps will reproduce the problem?

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start spyder with --new-instance option
Traceback (most recent call last):
  File "D:\GitHub\spyder\spyder\workers\updates.py", line 119, in start
    channel, channel_url = get_spyder_conda_channel()
  File "D:\GitHub\spyder\spyder\utils\conda.py", line 236, in get_spyder_conda_channel
    if "<develop>" in channel_url:
UnboundLocalError: local variable 'channel_url' referenced before assignment

### Traceback
```python-traceback
Traceback (most recent call last):
  File "D:\GitHub\spyder\spyder\workers\updates.py", line 119, in start
    channel, channel_url = get_spyder_conda_channel()
  File "D:\GitHub\spyder\spyder\utils\conda.py", line 236, in get_spyder_conda_channel
    if "<develop>" in channel_url:
UnboundLocalError: local variable 'channel_url' referenced before assignment
```

## Versions

* Spyder version: 5.5.4 eca9916d1 (conda)
* Python version: 3.9.19 64-bit
* Qt version: 5.15.8
* PyQt5 version: 5.15.9
* Operating System: Windows-10-10.0.19042-SP0

### Dependencies

```
# Mandatory:
atomicwrites >=1.2.0             :  1.4.1 (OK)
chardet >=2.0.0                  :  5.2.0 (OK)
cloudpickle >=0.5.0              :  3.0.0 (OK)
cookiecutter >=1.6.0             :  2.6.0 (OK)
diff_match_patch >=20181111      :  20230430 (OK)
intervaltree >=3.0.2             :  3.1.0 (OK)
IPython >=8.13.0,<9.0.0,!=8.17.1 :  8.18.1 (OK)
jedi >=0.17.2,<0.20.0            :  0.19.1 (OK)
jellyfish >=0.7                  :  1.0.3 (OK)
jsonschema >=3.2.0               :  4.22.0 (OK)
keyring >=17.0.0                 :  25.2.0 (OK)
nbconvert >=4.0                  :  7.16.4 (OK)
numpydoc >=0.6.0                 :  1.7.0 (OK)
paramiko >=2.4.0                 :  3.4.0 (OK)
parso >=0.7.0,<0.9.0             :  0.8.4 (OK)
pexpect >=4.4.0                  :  4.9.0 (OK)
pickleshare >=0.4                :  0.7.5 (OK)
psutil >=5.3                     :  5.9.8 (OK)
pygments >=2.0                   :  2.17.2 (OK)
pylint >=3.1,<4                  :  3.1.0 (OK)
pylint_venv >=3.0.2              :  3.0.3 (OK)
pyls_spyder >=0.4.0              :  0.4.0 (OK)
pylsp >=1.11.0,<1.12.0           :  1.11.0 (OK)
pylsp_black >=2.0.0,<3.0.0       :  2.0.0 (OK)
qdarkstyle >=3.2.0,<3.3.0        :  3.2.3 (OK)
qstylizer >=0.2.2                :  0.2.3 (OK)
qtawesome >=1.3.1,<1.4.0         :  1.3.1 (OK)
qtconsole >=5.5.1,<5.6.0         :  5.5.1 (OK)
qtpy >=2.1.0                     :  2.4.1 (OK)
rtree >=0.9.7                    :  1.2.0 (OK)
setuptools >=49.6.0              :  69.5.1 (OK)
sphinx >=0.6.6                   :  7.3.7 (OK)
spyder_kernels >=2.5.1,<2.6.0    :  2.5.1 (OK)
textdistance >=4.2.0             :  4.6.2 (OK)
three_merge >=0.1.1              :  0.1.1 (OK)
watchdog >=0.10.3                :  4.0.0 (OK)
zmq >=24.0.0                     :  26.0.2 (OK)

# Optional:
cython >=0.21                    :  None (NOK)
matplotlib >=3.0.0               :  None (NOK)
numpy >=1.7                      :  None (NOK)
pandas >=1.1.1                   :  None (NOK)
scipy >=0.17.0                   :  None (NOK)
sympy >=0.7.3                    :  None (NOK)
```



Discussion:
Hey @thinhld80, thanks for reporting. We'll take a look at this problem for our next version (5.5.5), to be released shortly.

Resolving patch:
diff --git a/spyder/utils/conda.py b/spyder/utils/conda.py
--- a/spyder/utils/conda.py
+++ b/spyder/utils/conda.py
@@ -232,6 +232,11 @@ def get_spyder_conda_channel():
     if 'error' in out:
         return None, None
 
+    # These variables can be unassigned after the next for, so we need to give
+    # them a default value at this point.
+    # Fixes spyder-ide/spyder#22054
+    channel, channel_url = None, None
+
     for package_info in out:
         if package_info["name"] == 'spyder':
             channel = package_info["channel"]


Test patch: