diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 29b2a6e9..1bbfee8f 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -65,8 +65,8 @@ jobs:
     - name: Add repositories for older GCC
       run: |
         # Below repo provides GCC 4.9.
-        sudo apt-add-repository 'deb http://azure.archive.ubuntu.com/ubuntu/ xenial main'
-        sudo apt-add-repository 'deb http://azure.archive.ubuntu.com/ubuntu/ xenial universe'
+        sudo apt-add-repository 'deb http://dk.archive.ubuntu.com/ubuntu/ xenial main'
+        sudo apt-add-repository 'deb http://dk.archive.ubuntu.com/ubuntu/ xenial universe'
       if: ${{ matrix.cxx == 'g++-4.9' }}
 
     - name: Add repositories for newer GCC
diff --git a/include/fmt/format.h b/include/fmt/format.h
index c7d75fd1..77797801 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -1869,20 +1869,19 @@ inline auto find_escape(const char* begin, const char* end)
   return result;
 }
 
-#define FMT_STRING_IMPL(s, base)                                              \
-  [] {                                                                        \
-    /* Use the hidden visibility as a workaround for a GCC bug (#1973). */    \
-    /* Use a macro-like name to avoid shadowing warnings. */                  \
-    struct FMT_VISIBILITY("hidden") FMT_COMPILE_STRING : base {               \
-      using char_type FMT_MAYBE_UNUSED = fmt::remove_cvref_t<decltype(s[0])>; \
-      FMT_MAYBE_UNUSED FMT_CONSTEXPR explicit                                 \
-      operator fmt::basic_string_view<char_type>() const {                    \
-        return fmt::detail_exported::compile_string_to_view<char_type>(s);    \
-      }                                                                       \
-    };                                                                        \
-    typename FMT_COMPILE_STRING::char_type FMT_CHAR = {};                     \
-    (void)FMT_CHAR;                                                           \
-    return FMT_COMPILE_STRING();                                              \
+#define FMT_STRING_IMPL(s, base)                                           \
+  [] {                                                                     \
+    /* Use the hidden visibility as a workaround for a GCC bug (#1973). */ \
+    /* Use a macro-like name to avoid shadowing warnings. */               \
+    struct FMT_VISIBILITY("hidden") FMT_COMPILE_STRING : base {            \
+      using char_type = fmt::remove_cvref_t<decltype(s[0])>;               \
+      FMT_MAYBE_UNUSED FMT_CONSTEXPR explicit                              \
+      operator fmt::basic_string_view<char_type>() const {                 \
+        return fmt::detail_exported::compile_string_to_view<char_type>(s); \
+      }                                                                    \
+    };                                                                     \
+    fmt::detail::ignore_unused(typename FMT_COMPILE_STRING::char_type());  \
+    return FMT_COMPILE_STRING();                                           \
   }()
 
 /**