lib/fmt: require libfmt 9

Version 9 added the "debug format" which I'd like to use.

src/lib/fmt/RuntimeError.hxx

@@ -4,9 +4,6 @@
 #pragma once
 
 #include <fmt/core.h>
-#if FMT_VERSION >= 80000 && FMT_VERSION < 90000
-#include <fmt/format.h>
-#endif
 
 #include <stdexcept> // IWYU pragma: export
 
@@ -19,14 +16,8 @@ template<typename S, typename... Args>
 auto
 FmtRuntimeError(const S &format_str, Args&&... args) noexcept
 {
-#if FMT_VERSION >= 90000
 	return VFmtRuntimeError(format_str,
 				fmt::make_format_args(args...));
-#else
-	return VFmtRuntimeError(fmt::to_string_view(format_str),
-				fmt::make_args_checked<Args...>(format_str,
-								args...));
-#endif
 }
 
 [[nodiscard]] [[gnu::pure]]
@@ -38,12 +29,6 @@ template<typename S, typename... Args>
 auto
 FmtInvalidArgument(const S &format_str, Args&&... args) noexcept
 {
-#if FMT_VERSION >= 90000
 	return VFmtInvalidArgument(format_str,
 				fmt::make_format_args(args...));
-#else
-	return VFmtInvalidArgument(fmt::to_string_view(format_str),
-				fmt::make_args_checked<Args...>(format_str,
-								args...));
-#endif
 }

src/lib/fmt/SystemError.hxx

@@ -6,9 +6,6 @@
 #include "system/Error.hxx" // IWYU pragma: export
 
 #include <fmt/core.h>
-#if FMT_VERSION >= 80000 && FMT_VERSION < 90000
-#include <fmt/format.h>
-#endif
 
 #include <type_traits>
 
@@ -23,14 +20,8 @@ std::system_error
 FmtSystemError(std::error_code code,
 	       const S &format_str, Args&&... args) noexcept
 {
-#if FMT_VERSION >= 90000
 	return VFmtSystemError(code, format_str,
 			       fmt::make_format_args(args...));
-#else
-	return VFmtSystemError(code, fmt::to_string_view(format_str),
-			       fmt::make_args_checked<Args...>(format_str,
-							       args...));
-#endif
 }
 
 #ifdef _WIN32
@@ -46,14 +37,8 @@ std::system_error
 FmtLastError(DWORD code,
 	     const S &format_str, Args&&... args) noexcept
 {
-#if FMT_VERSION >= 90000
 	return VFmtLastError(code, format_str,
 			     fmt::make_format_args(args...));
-#else
-	return VFmtLastError(code, fmt::to_string_view(format_str),
-			     fmt::make_args_checked<Args...>(format_str,
-							     args...));
-#endif
 }
 
 template<typename S, typename... Args>

src/lib/fmt/ToBuffer.hxx

@@ -6,9 +6,6 @@
 #include "util/StringBuffer.hxx"
 
 #include <fmt/core.h>
-#if FMT_VERSION < 90000
-#include <fmt/format.h> // for the fmt::buffer::flush() implementation
-#endif
 
 template<std::size_t size>
 StringBuffer<size> &
@@ -35,14 +32,8 @@ StringBuffer<size> &
 FmtToBuffer(StringBuffer<size> &buffer,
 	    const S &format_str, Args&&... args) noexcept
 {
-#if FMT_VERSION >= 90000
 	return VFmtToBuffer(buffer, format_str,
 			    fmt::make_format_args(args...));
-#else
-	return VFmtToBuffer(buffer, fmt::to_string_view(format_str),
-			    fmt::make_args_checked<Args...>(format_str,
-							    args...));
-#endif
 }
 
 template<std::size_t size, typename S, typename... Args>
@@ -50,12 +41,6 @@ template<std::size_t size, typename S, typename... Args>
 auto
 FmtBuffer(const S &format_str, Args&&... args) noexcept
 {
-#if FMT_VERSION >= 90000
 	return VFmtBuffer<size>(format_str,
 				fmt::make_format_args(args...));
-#else
-	return VFmtBuffer<size>(fmt::to_string_view(format_str),
-				fmt::make_args_checked<Args...>(format_str,
-								args...));
-#endif
 }

src/lib/fmt/meson.build

@@ -1,4 +1,4 @@
-libfmt = dependency('fmt', version: '>= 7', fallback: ['fmt', 'fmt_dep'])
+libfmt = dependency('fmt', version: '>= 9', fallback: ['fmt', 'fmt_dep'])
 
 if compiler.get_id() == 'clang' and compiler.version().version_compare('<15')
   libfmt = declare_dependency(