[SVS] Add support for GLIBC 2.26 systems and GCC v11.2. E.g. AmazonLinux 2 (#720)

* [SVS] Add support for GLIBC 2.26 systems. E.g. AmazonLinux 2

* Workaround GCC v11.2 C++20 compatibility issue

* fixup! [SVS] Add support for GLIBC 2.26 systems. E.g. AmazonLinux 2

Author: rfsaliev

cmake/svs.cmake

@@ -42,17 +42,34 @@ if(USE_SVS)
 
     # detect if build environment is using glibc
     include(CheckSymbolExists)
-    unset(GLIBC_FOUND CACHE)
     check_symbol_exists(__GLIBC__ "features.h" GLIBC_FOUND)
-    if(NOT GLIBC_FOUND)
-        message(STATUS "GLIBC is not detected - SVS shared library is not supported")
+    if(GLIBC_FOUND)
+        include(CheckCXXSourceRuns)
+        check_cxx_source_runs("#include <features.h>
+            int main(){ return __GLIBC__ == 2 && __GLIBC_MINOR__ >= 28 ?0:1; }"
+            GLIBC_2_28_FOUND)
+        check_cxx_source_runs("#include <features.h>
+            int main(){ return __GLIBC__ == 2 && __GLIBC_MINOR__ >= 26 ?0:1; }"
+            GLIBC_2_26_FOUND)
     endif()
 
     cmake_dependent_option(SVS_SHARED_LIB "Use SVS pre-compiled shared library" ON "USE_SVS AND GLIBC_FOUND AND SVS_LVQ_SUPPORTED" OFF)
     if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-        set(SVS_URL "https://github.com/intel/ScalableVectorSearch/releases/download/v0.0.8-dev/svs-shared-library-0.0.8-NIGHTLY-20250629-clang.tar.gz" CACHE STRING "SVS URL")
+        if (GLIBC_2_28_FOUND)
+            set(SVS_URL "https://github.com/intel/ScalableVectorSearch/releases/download/v0.0.8-dev/svs-shared-library-0.0.8-NIGHTLY-20250629-clang.tar.gz" CACHE STRING "SVS URL")
+        else()
+            message(STATUS "GLIBC>=2.28 is required for Clang build - disabling SVS_SHARED_LIB")
+            set(SVS_SHARED_LIB OFF)
+        endif()
     else()
-        set(SVS_URL "https://github.com/intel/ScalableVectorSearch/releases/download/v0.0.8-dev/svs-shared-library-0.0.8-NIGHTLY-20250630.tar.gz" CACHE STRING "SVS URL")
+        if (GLIBC_2_28_FOUND)
+            set(SVS_URL "https://github.com/intel/ScalableVectorSearch/releases/download/v0.0.8-dev/svs-shared-library-0.0.8-NIGHTLY-20250630.tar.gz" CACHE STRING "SVS URL")
+        elseif(GLIBC_2_26_FOUND)
+            set(SVS_URL "https://github.com/intel/ScalableVectorSearch/releases/download/v0.0.8-dev/svs-shared-library-0.0.8-NIGHTLY-20250701-glibc-2_26.tar.gz" CACHE STRING "SVS URL")
+        else()
+            message(STATUS "GLIBC>=2.26 is required for SVS shared library - disabling SVS_SHARED_LIB")
+            set(SVS_SHARED_LIB OFF)
+        endif()
     endif()
 
     if(SVS_SHARED_LIB)

tests/unit/test_svs.cpp

@@ -2790,7 +2790,7 @@ TYPED_TEST(SVSTest, logging_runtime_params) {
     index_logger->critical("Custom log critical");
     index_logger->flush();
     // Check that the log messages are written to the ostringstream
-    auto index_log = os_index.view();
+    auto index_log = os_index.str();
     EXPECT_NE(index_log.find("Custom log trace"), std::string::npos);
     EXPECT_NE(index_log.find("Custom log debug"), std::string::npos);
     EXPECT_NE(index_log.find("Custom log info"), std::string::npos);
@@ -2800,7 +2800,7 @@ TYPED_TEST(SVSTest, logging_runtime_params) {
 
     VecSimIndex_Free(index);
 
-    auto global_log = os_global.view();
+    auto global_log = os_global.str();
     EXPECT_TRUE(global_log.empty()) << "Global log should be empty, but got: " << global_log;
 }