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Disable LTO for ZLIB #19

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Merged
jviotti merged 1 commit into from
Mar 16, 2026
Merged

Disable LTO for ZLIB #19

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6 changes: 6 additions & 0 deletions cmake/FindZLIB.cmake
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Original file line number Diff line number Diff line change
Expand Up @@ -64,6 +64,12 @@ if(NOT ZLIB_FOUND)
-fno-math-errno
-fwrapv)
endif()

# Disable LTO for zlib to work around GCC LTO linker plugin not
# properly rescanning this archive for transitive dependencies
if(HYDRA_COMPILER_GCC)
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@cubic-dev-ai cubic-dev-ai bot Mar 13, 2026 •
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P2: Scope this LTO workaround to static zlib builds; as written it also disables LTO for shared builds that are not affected by the archive-rescan issue.

Prompt for AI agents 
Check if this issue is valid — if so, understand the root cause and fix it. At cmake/FindZLIB.cmake, line 70:

<comment>Scope this LTO workaround to static zlib builds; as written it also disables LTO for shared builds that are not affected by the archive-rescan issue.</comment>

<file context>
@@ -64,6 +64,12 @@ if(NOT ZLIB_FOUND)
+
+    # Disable LTO for zlib to work around GCC LTO linker plugin not
+    # properly rescanning this archive for transitive dependencies
+    if(HYDRA_COMPILER_GCC)
+      target_compile_options(zlib PRIVATE -fno-lto)
+    endif()
</file context>
Suggested change
if(HYDRA_COMPILER_GCC)
if(HYDRA_COMPILER_GCC AND NOT BUILD_SHARED_LIBS)
Fix with Cubic

target_compile_options(zlib PRIVATE -fno-lto)
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@augmentcode augmentcode bot Mar 13, 2026

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If the project enables LTO globally (e.g., via INTERPROCEDURAL_OPTIMIZATION/CMAKE_INTERPROCEDURAL_OPTIMIZATION), it’s worth double-checking that adding -fno-lto here reliably overrides any injected -flto so zlib is truly built non-LTO in those configurations. Otherwise the GCC LTO plugin issue this comment mentions could still reproduce.

Severity: medium

Fix This in Augment

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endif()
endif()

target_include_directories(zlib PUBLIC
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