Xcode 26 Bug: URLs with percent encoding query parameters won't compile

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sgilroy-grx OP

Created 1w

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Just repro'd in the latest Xcode 26 Beta 3. Building an iOS app using xcstrings for localization.

We have a URL that uses percent encoding for a query param. For example:

Screenshot 2025-07-08 at 4.27.10 PM.png

Upon compiling in the latest Xcode 26 beta this fails with:

Unable to create a Swift type from the format specifier “%20S”.

This was not the case in prior Xcode versions.

Answered by Developer Tools Engineer in 848357022

Hi there! Unfortunately, the string catalog is interpreting the %20S as a format specifier for a variable substitution, rather than the encoded URL. The workaround here would be to disable generating a symbol for this particular string. You can do so by selecting the string, opening the Attributes inspector on the right, and unchecking "Generate Swift Symbol".

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Answer 1

Developer Tools Engineer OP

Apple

1w

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Hi there! Unfortunately, the string catalog is interpreting the %20S as a format specifier for a variable substitution, rather than the encoded URL. The workaround here would be to disable generating a symbol for this particular string. You can do so by selecting the string, opening the Attributes inspector on the right, and unchecking "Generate Swift Symbol".

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