Conflicting no_proxy and NO_PROXY Values on Linux
Find conflicting no_proxy and NO_PROXY values before assuming that two clients received the same direct-routing policy.
A Linux process can inherit both of these values:
NO_PROXY=old.office.example
no_proxy=new.office.exampleThey are separate names in a case-sensitive environment. A client supporting both may select just one nonempty value, so printing only NO_PROXY can miss the policy it actually uses.
| Specific implementation | Priority when both are nonempty |
|---|---|
| Go 1.27.3's vendored environment proxy helper | Uppercase before lowercase |
| Requests 2.34.2 bypass lookup | Lowercase before uppercase |
Inspect both spellings at the failing process's launch boundary. Its service unit, shell profile, container definition or job runner may supply the surviving value. Fix the source of the conflict, rather than replacing the proxy server while two different policies remain.
Give the participating programs the intended list through their supported configuration. If compatibility requires both spellings, keep the values synchronized. Record the selected proxy endpoint variables too: one client's endpoint combined with another client's bypass list is not a controlled comparison.
The table describes those source versions, not all future Go programs or Python libraries. Windows also has different environment-name case semantics; inspect what its process stores instead of assuming that it reproduces the Linux two-name conflict.