Fix cmake, add learning to CLAUDE.md

CLAUDE.md

@@ -243,6 +243,11 @@ from an implementation detail instead of an explicit option.
 * Don't manually edit BUCK file, after updating src.mk, run
     /usr/local/bin/python3 buckifier/buckify_rocksdb.py to update it
 * For -j in make command, use the number of CPU cores to decide it.
+* When searching for references to something (a symbol, library, etc.), do not
+  restrict or truncate your search based on presumed relevance or scope. It is
+  important and time-saving to keep the repo reasonably consistent across
+  different build systems, programming languages, and even between
+  documentation and implementation.
 
 ### Avoiding mixed build modes with Make (use `AUTO_CLEAN=1`)
 

CMakeLists.txt

@@ -698,10 +698,19 @@ if(USE_FOLLY)
 
     include(${FOLLY_INST_PATH}/lib/cmake/folly/folly-config.cmake)
 
-    # Fix gflags library name for debug builds
+    # Fix gflags library name for debug builds. The getdeps gflags shared
+    # library is versioned (e.g. libgflags_debug.so.2.3), so resolve the
+    # actual file by glob rather than hard-coding a version.
     if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+      file(GLOB GFLAGS_DEBUG_SHARED_LIBS
+        "${GFLAGS_INST_PATH}/lib/libgflags_debug.so.*")
+      if(NOT GFLAGS_DEBUG_SHARED_LIBS)
+        message(FATAL_ERROR
+          "Could not find getdeps libgflags_debug.so under ${GFLAGS_INST_PATH}/lib")
+      endif()
+      list(GET GFLAGS_DEBUG_SHARED_LIBS 0 GFLAGS_DEBUG_SHARED_LIB)
       set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,-rpath=${GFLAGS_INST_PATH}/lib")
-      set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${GFLAGS_INST_PATH}/lib/libgflags_debug.so.2.2")
+      set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${GFLAGS_DEBUG_SHARED_LIB}")
     endif()
   endif()