spdlog: reformat expression arguments, and comment about fmt_9

pkgs/applications/science/electronics/hal-hardware-analyzer/default.nix

@@ -41,7 +41,7 @@ let
   # no stable hal release yet with recent spdlog/fmt support, remove
   # once 4.0.0 is released - see https://github.com/emsec/hal/issues/452
   spdlog' = spdlog.override {
-    fmt = fmt_8.overrideAttrs (_: rec {
+    fmt_9 = fmt_8.overrideAttrs (_: rec {
       version = "8.0.1";
       src = fetchFromGitHub {
         owner = "fmtlib";

pkgs/development/libraries/spdlog/default.nix

@@ -1,4 +1,12 @@
-{ lib, stdenv, fetchFromGitHub, fetchpatch, cmake, fmt
+{ lib
+, stdenv
+, fetchFromGitHub
+, fetchpatch
+, cmake
+# Although we include upstream patches that fix compilation with fmt_10, we
+# still use fmt_9 because this dependency is propagated, and many of spdlog's
+# reverse dependencies don't support fmt_10 yet.
+, fmt_9
 , staticBuild ? stdenv.hostPlatform.isStatic
 
 # tests
@@ -29,7 +37,7 @@ stdenv.mkDerivation rec {
   ];
 
   nativeBuildInputs = [ cmake ];
-  propagatedBuildInputs = [ fmt ];
+  propagatedBuildInputs = [ fmt_9 ];
 
   cmakeFlags = [
     "-DSPDLOG_BUILD_SHARED=${if staticBuild then "OFF" else "ON"}"

pkgs/top-level/all-packages.nix

@@ -40672,9 +40672,7 @@ with pkgs;
     inherit (darwin.apple_sdk.frameworks) Cocoa OpenGL;
   };
 
-  spdlog = callPackage ../development/libraries/spdlog {
-    fmt = fmt_9;
-  };
+  spdlog = callPackage ../development/libraries/spdlog { };
 
   dart = callPackage ../development/compilers/dart { };