5 files changed, 6 insertions, 6 deletions
diff --git a/pkgs/servers/mail/archiveopteryx/default.nix b/pkgs/servers/mail/archiveopteryx/default.nix
index 2bcd87c3b84..99e482323a4 100644
--- a/pkgs/servers/mail/archiveopteryx/default.nix
+++ b/pkgs/servers/mail/archiveopteryx/default.nix
@@ -21,7 +21,7 @@ stdenv.mkDerivation rec {
   '';
 
   # fix build on gcc7+ and gcc11+
-  NIX_CFLAGS_COMPILE = [
+  env.NIX_CFLAGS_COMPILE = toString ([
     "-std=c++11" # c++17+ has errors
     "-Wno-error=builtin-declaration-mismatch"
     "-Wno-error=deprecated-copy"
@@ -29,7 +29,7 @@ stdenv.mkDerivation rec {
     "-Wno-error=nonnull"
   ] ++ lib.optionals (stdenv.cc.isGNU && lib.versionAtLeast stdenv.cc.version "11") [
     "-Wno-error=mismatched-new-delete"
-  ];
+  ]);
 
   buildPhase = ''jam "-j$NIX_BUILD_CORES" '';
   installPhase = ''
diff --git a/pkgs/servers/mail/dspam/default.nix b/pkgs/servers/mail/dspam/default.nix
index 852de800a6c..f32316428a6 100644
--- a/pkgs/servers/mail/dspam/default.nix
+++ b/pkgs/servers/mail/dspam/default.nix
@@ -68,7 +68,7 @@ in stdenv.mkDerivation rec {
   # gcc-10. Otherwise build fails as:
   #   ld: .libs/hash_drv.o:/build/dspam-3.10.2/src/util.h:96: multiple definition of `verified_user';
   #     .libs/libdspam.o:/build/dspam-3.10.2/src/util.h:96: first defined here
-  NIX_CFLAGS_COMPILE = "-fcommon";
+  env.NIX_CFLAGS_COMPILE = "-fcommon";
 
   # Lots of things are hardwired to paths like sysconfdir. That's why we install with both "prefix" and "DESTDIR"
   # and fix directory structure manually after that.
diff --git a/pkgs/servers/mail/mlmmj/default.nix b/pkgs/servers/mail/mlmmj/default.nix
index aba0664b8f4..2795ba1af35 100644
--- a/pkgs/servers/mail/mlmmj/default.nix
+++ b/pkgs/servers/mail/mlmmj/default.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
   # gcc-10. Otherwise build fails as:
   #   ld: getlistdelim.o:/build/mlmmj-1.3.0/src/../include/mlmmj.h:84: multiple definition of
   #     `subtype_strs'; mlmmj-send.o:/build/mlmmj-1.3.0/src/../include/mlmmj.h:84: first defined here
-  NIX_CFLAGS_COMPILE = "-fcommon";
+  env.NIX_CFLAGS_COMPILE = "-fcommon";
 
   postInstall = ''
     # grab all documentation files
diff --git a/pkgs/servers/mail/opensmtpd/extras.nix b/pkgs/servers/mail/opensmtpd/extras.nix
index 5759e57d3b4..f179bf96368 100644
--- a/pkgs/servers/mail/opensmtpd/extras.nix
+++ b/pkgs/servers/mail/opensmtpd/extras.nix
@@ -68,7 +68,7 @@ stdenv.mkDerivation rec {
     "--with-table-redis"
   ];
 
-  NIX_CFLAGS_COMPILE = lib.optionalString enableRedis
+  env.NIX_CFLAGS_COMPILE = lib.optionalString enableRedis
       "-I${hiredis}/include/hiredis -lhiredis"
     + lib.optionalString enableMysql
       " -L${libmysqlclient}/lib/mysql";
diff --git a/pkgs/servers/mail/postfix/pfixtools.nix b/pkgs/servers/mail/postfix/pfixtools.nix
index df04ade5b45..d57aaa4ef29 100644
--- a/pkgs/servers/mail/postfix/pfixtools.nix
+++ b/pkgs/servers/mail/postfix/pfixtools.nix
@@ -42,7 +42,7 @@ stdenv.mkDerivation {
                       --replace /bin/bash ${bash}/bin/bash;
   '';
 
-  NIX_CFLAGS_COMPILE = "-Wno-error=unused-result -Wno-error=nonnull-compare -Wno-error=format-truncation";
+  env.NIX_CFLAGS_COMPILE = "-Wno-error=unused-result -Wno-error=nonnull-compare -Wno-error=format-truncation";
 
   makeFlags = [ "DESTDIR=$(out)" "prefix=" ];