the glibc codepath uses res_ninit/res_nclose, which are not implemented in musl
--- a/net/dns/dns_reloader.cc
+++ b/net/dns/dns_reloader.cc
@@ -6,8 +6,7 @@
 
 #include "build/build_config.h"
 
-#if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_APPLE) && !BUILDFLAG(IS_OPENBSD) && \
-    !BUILDFLAG(IS_ANDROID) && !BUILDFLAG(IS_FUCHSIA)
+#if defined(__GLIBC__)
 
 #include <resolv.h>
 
--- a/net/dns/host_resolver_system_task.cc
+++ b/net/dns/host_resolver_system_task.cc
@@ -310,8 +310,7 @@
 }
 
 void EnsureSystemHostResolverCallReady() {
-#if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_APPLE) && !BUILDFLAG(IS_OPENBSD) && \
-    !BUILDFLAG(IS_ANDROID)
+#if defined(__GLIBC__)
   EnsureDnsReloaderInit();
 #elif BUILDFLAG(IS_WIN)
   EnsureWinsockInit();
@@ -396,8 +396,7 @@
   base::ScopedBlockingCall scoped_blocking_call(FROM_HERE,
                                                 base::BlockingType::WILL_BLOCK);
 
-#if BUILDFLAG(IS_POSIX) && \
-    !(BUILDFLAG(IS_APPLE) || BUILDFLAG(IS_OPENBSD) || BUILDFLAG(IS_ANDROID))
+#if defined(__GLIBC__)
   DnsReloaderMaybeReload();
 #endif
   auto [ai, err, os_error] = AddressInfo::Get(host, hints, nullptr, network);