diff --git a/tests/functional/add.sh b/tests/functional/add.sh
index a6cf88e1a..328b14831 100755
--- a/tests/functional/add.sh
+++ b/tests/functional/add.sh
@@ -31,6 +31,8 @@ test "$hash1" = "sha256:$hash2"
 
 #### New style commands
 
+TODO_NixOS
+
 clearStore
 
 (
diff --git a/tests/functional/binary-cache-build-remote.sh b/tests/functional/binary-cache-build-remote.sh
index 4edda85b6..17e8bdcc1 100755
--- a/tests/functional/binary-cache-build-remote.sh
+++ b/tests/functional/binary-cache-build-remote.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 clearCacheCache
 
diff --git a/tests/functional/binary-cache.sh b/tests/functional/binary-cache.sh
index 5ef6d89d4..6a177b657 100755
--- a/tests/functional/binary-cache.sh
+++ b/tests/functional/binary-cache.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 needLocalStore "'--no-require-sigs' can’t be used with the daemon"
 
 # We can produce drvs directly into the binary cache
diff --git a/tests/functional/brotli.sh b/tests/functional/brotli.sh
index 672e771c2..327eab4a5 100755
--- a/tests/functional/brotli.sh
+++ b/tests/functional/brotli.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 clearCache
 
diff --git a/tests/functional/build-delete.sh b/tests/functional/build-delete.sh
index 59cf95bd2..2ebf1fd3d 100755
--- a/tests/functional/build-delete.sh
+++ b/tests/functional/build-delete.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 # https://github.com/NixOS/nix/issues/6572
diff --git a/tests/functional/build-dry.sh b/tests/functional/build-dry.sh
index dca5888a6..cff0f9a49 100755
--- a/tests/functional/build-dry.sh
+++ b/tests/functional/build-dry.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 ###################################################
 # Check that --dry-run isn't confused with read-only mode
 # https://github.com/NixOS/nix/issues/1795
diff --git a/tests/functional/build-remote-trustless-should-fail-0.sh b/tests/functional/build-remote-trustless-should-fail-0.sh
index 269f7f112..4eccb73e0 100755
--- a/tests/functional/build-remote-trustless-should-fail-0.sh
+++ b/tests/functional/build-remote-trustless-should-fail-0.sh
@@ -4,6 +4,7 @@ source common.sh
 
 enableFeatures "daemon-trust-override"
 
+TODO_NixOS
 restartDaemon
 
 requireSandboxSupport
diff --git a/tests/functional/build-remote-trustless-should-pass-2.sh b/tests/functional/build-remote-trustless-should-pass-2.sh
index ba5d1ff7a..34ce7fbe4 100755
--- a/tests/functional/build-remote-trustless-should-pass-2.sh
+++ b/tests/functional/build-remote-trustless-should-pass-2.sh
@@ -4,6 +4,8 @@ source common.sh
 
 enableFeatures "daemon-trust-override"
 
+TODO_NixOS
+
 restartDaemon
 
 # Remote doesn't trust us
diff --git a/tests/functional/build-remote-trustless-should-pass-3.sh b/tests/functional/build-remote-trustless-should-pass-3.sh
index 187b89948..d01d79191 100755
--- a/tests/functional/build-remote-trustless-should-pass-3.sh
+++ b/tests/functional/build-remote-trustless-should-pass-3.sh
@@ -4,6 +4,7 @@ source common.sh
 
 enableFeatures "daemon-trust-override"
 
+TODO_NixOS
 restartDaemon
 
 # Remote doesn't trusts us, but this is fine because we are only
diff --git a/tests/functional/build.sh b/tests/functional/build.sh
index a14e6d672..db759b6e9 100755
--- a/tests/functional/build.sh
+++ b/tests/functional/build.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 # Make sure that 'nix build' returns all outputs by default.
diff --git a/tests/functional/ca/common.sh b/tests/functional/ca/common.sh
index b104b5a78..48f1ac46b 100644
--- a/tests/functional/ca/common.sh
+++ b/tests/functional/ca/common.sh
@@ -2,4 +2,6 @@ source ../common.sh
 
 enableFeatures "ca-derivations"
 
+TODO_NixOS
+
 restartDaemon
diff --git a/tests/functional/case-hack.sh b/tests/functional/case-hack.sh
index 48a2ab13f..feddc6583 100755
--- a/tests/functional/case-hack.sh
+++ b/tests/functional/case-hack.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 rm -rf "$TEST_ROOT/case"
diff --git a/tests/functional/check-refs.sh b/tests/functional/check-refs.sh
index 6534e55c6..26790c11b 100755
--- a/tests/functional/check-refs.sh
+++ b/tests/functional/check-refs.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 RESULT=$TEST_ROOT/result
diff --git a/tests/functional/check-reqs.sh b/tests/functional/check-reqs.sh
index 4d795391e..bb91bacde 100755
--- a/tests/functional/check-reqs.sh
+++ b/tests/functional/check-reqs.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 RESULT=$TEST_ROOT/result
diff --git a/tests/functional/check.sh b/tests/functional/check.sh
index efb93eeb0..8f602b487 100755
--- a/tests/functional/check.sh
+++ b/tests/functional/check.sh
@@ -15,6 +15,8 @@ checkBuildTempDirRemoved ()
 # written to build temp directories to verify created by this instance
 checkBuildId=$(date +%s%N)
 
+TODO_NixOS
+
 clearStore
 
 nix-build dependencies.nix --no-out-link
@@ -76,6 +78,8 @@ grep 'may not be deterministic' $TEST_ROOT/log
 [ "$status" = "104" ]
 if checkBuildTempDirRemoved $TEST_ROOT/log; then false; fi
 
+TODO_NixOS
+
 clearStore
 
 path=$(nix-build check.nix -A fetchurl --no-out-link)
diff --git a/tests/functional/chroot-store.sh b/tests/functional/chroot-store.sh
index 741907fca..03803a2b9 100755
--- a/tests/functional/chroot-store.sh
+++ b/tests/functional/chroot-store.sh
@@ -39,6 +39,8 @@ EOF
 
     cp simple.nix shell.nix simple.builder.sh config.nix "$flakeDir/"
 
+    TODO_NixOS
+
     outPath=$(nix build --print-out-paths --no-link --sandbox-paths '/nix? /bin? /lib? /lib64? /usr?' --store "$TEST_ROOT/x" path:"$flakeDir")
 
     [[ $outPath =~ ^/nix2/store/.*-simple$ ]]
diff --git a/tests/functional/compression-levels.sh b/tests/functional/compression-levels.sh
index 6a2111f10..f51c3f509 100755
--- a/tests/functional/compression-levels.sh
+++ b/tests/functional/compression-levels.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 clearCache
 
diff --git a/tests/functional/config.sh b/tests/functional/config.sh
index 1811b755c..50858eaa4 100755
--- a/tests/functional/config.sh
+++ b/tests/functional/config.sh
@@ -28,6 +28,8 @@ nix registry remove userhome-with-xdg
 # Assert the .config folder hasn't been created.
 [ ! -e "$HOME/.config" ]
 
+TODO_NixOS # Very specific test setup not compatible with the NixOS test environment?
+
 # Test that files are loaded from XDG by default
 export XDG_CONFIG_HOME=$TEST_ROOT/confighome
 export XDG_CONFIG_DIRS=$TEST_ROOT/dir1:$TEST_ROOT/dir2
diff --git a/tests/functional/db-migration.sh b/tests/functional/db-migration.sh
index a6a5c7744..6feabb90d 100755
--- a/tests/functional/db-migration.sh
+++ b/tests/functional/db-migration.sh
@@ -10,6 +10,8 @@ if [[ -z "${NIX_DAEMON_PACKAGE-}" ]]; then
     skipTest "not using the Nix daemon"
 fi
 
+TODO_NixOS
+
 killDaemon
 
 # Fill the db using the older Nix
diff --git a/tests/functional/debugger.sh b/tests/functional/debugger.sh
index 47e644bb7..178822d79 100755
--- a/tests/functional/debugger.sh
+++ b/tests/functional/debugger.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 # regression #9932
diff --git a/tests/functional/dependencies.sh b/tests/functional/dependencies.sh
index 1b266935d..bb01b3988 100755
--- a/tests/functional/dependencies.sh
+++ b/tests/functional/dependencies.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 drvPath=$(nix-instantiate dependencies.nix)
diff --git a/tests/functional/dump-db.sh b/tests/functional/dump-db.sh
index 2d0460275..14181b4b6 100755
--- a/tests/functional/dump-db.sh
+++ b/tests/functional/dump-db.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 needLocalStore "--dump-db requires a local store"
 
 clearStore
diff --git a/tests/functional/dyn-drv/common.sh b/tests/functional/dyn-drv/common.sh
index c786f6925..0d95881b6 100644
--- a/tests/functional/dyn-drv/common.sh
+++ b/tests/functional/dyn-drv/common.sh
@@ -5,4 +5,6 @@ requireDaemonNewerThan "2.16.0pre20230419"
 
 enableFeatures "ca-derivations dynamic-derivations"
 
+TODO_NixOS
+
 restartDaemon
diff --git a/tests/functional/eval-store.sh b/tests/functional/eval-store.sh
index 0ab608acc..202e7b004 100755
--- a/tests/functional/eval-store.sh
+++ b/tests/functional/eval-store.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 # Using `--eval-store` with the daemon will eventually copy everything
 # to the build store, invalidating most of the tests here
 needLocalStore "“--eval-store” doesn't achieve much with the daemon"
diff --git a/tests/functional/eval.sh b/tests/functional/eval.sh
index acd6e2915..ba335d73a 100755
--- a/tests/functional/eval.sh
+++ b/tests/functional/eval.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 testStdinHeredoc=$(nix eval -f - <<EOF
diff --git a/tests/functional/export-graph.sh b/tests/functional/export-graph.sh
index 281b5b05b..b507b6d3a 100755
--- a/tests/functional/export-graph.sh
+++ b/tests/functional/export-graph.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 clearProfiles
 
diff --git a/tests/functional/export.sh b/tests/functional/export.sh
index fce2e333a..3e895a540 100755
--- a/tests/functional/export.sh
+++ b/tests/functional/export.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 outPath=$(nix-build dependencies.nix --no-out-link)
diff --git a/tests/functional/fetchClosure.sh b/tests/functional/fetchClosure.sh
index 4026b0790..7ef635d36 100755
--- a/tests/functional/fetchClosure.sh
+++ b/tests/functional/fetchClosure.sh
@@ -4,6 +4,8 @@ source common.sh
 
 enableFeatures "fetch-closure"
 
+TODO_NixOS
+
 clearStore
 clearCacheCache
 
diff --git a/tests/functional/fetchGit.sh b/tests/functional/fetchGit.sh
index d89d59a81..130b620bf 100755
--- a/tests/functional/fetchGit.sh
+++ b/tests/functional/fetchGit.sh
@@ -4,6 +4,8 @@ source common.sh
 
 requireGit
 
+TODO_NixOS
+
 clearStore
 
 # Intentionally not in a canonical form
diff --git a/tests/functional/fetchGitRefs.sh b/tests/functional/fetchGitRefs.sh
index 9373146cd..6d1f67e48 100755
--- a/tests/functional/fetchGitRefs.sh
+++ b/tests/functional/fetchGitRefs.sh
@@ -4,6 +4,8 @@ source common.sh
 
 requireGit
 
+TODO_NixOS
+
 clearStore
 
 repo="$TEST_ROOT/git"
diff --git a/tests/functional/fetchGitSubmodules.sh b/tests/functional/fetchGitSubmodules.sh
index 7c5f7b0d6..3726ee689 100755
--- a/tests/functional/fetchGitSubmodules.sh
+++ b/tests/functional/fetchGitSubmodules.sh
@@ -6,6 +6,8 @@ set -u
 
 requireGit
 
+TODO_NixOS
+
 clearStore
 
 rootRepo=$TEST_ROOT/gitSubmodulesRoot
diff --git a/tests/functional/fetchGitVerification.sh b/tests/functional/fetchGitVerification.sh
index 27f9a8cf5..57a317bcd 100755
--- a/tests/functional/fetchGitVerification.sh
+++ b/tests/functional/fetchGitVerification.sh
@@ -7,6 +7,8 @@ requireGit
 
 enableFeatures "verified-fetches"
 
+TODO_NixOS
+
 clearStore
 
 repo="$TEST_ROOT/git"
diff --git a/tests/functional/fetchMercurial.sh b/tests/functional/fetchMercurial.sh
index f3774fc74..6de192865 100755
--- a/tests/functional/fetchMercurial.sh
+++ b/tests/functional/fetchMercurial.sh
@@ -4,6 +4,8 @@ source common.sh
 
 [[ $(type -p hg) ]] || skipTest "Mercurial not installed"
 
+TODO_NixOS
+
 clearStore
 
 # Intentionally not in a canonical form
diff --git a/tests/functional/fetchTree-file.sh b/tests/functional/fetchTree-file.sh
index 6faccd282..66be928c7 100755
--- a/tests/functional/fetchTree-file.sh
+++ b/tests/functional/fetchTree-file.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 cd "$TEST_ROOT"
diff --git a/tests/functional/fetchurl.sh b/tests/functional/fetchurl.sh
index 2255dbbdc..5af44fcf2 100755
--- a/tests/functional/fetchurl.sh
+++ b/tests/functional/fetchurl.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 # Test fetching a flat file.
diff --git a/tests/functional/fixed.sh b/tests/functional/fixed.sh
index 4d07d00cd..d98769e64 100755
--- a/tests/functional/fixed.sh
+++ b/tests/functional/fixed.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 path=$(nix-store -q $(nix-instantiate fixed.nix -A good.0))
diff --git a/tests/functional/flakes/config.sh b/tests/functional/flakes/config.sh
index 66b917457..4f3906118 100755
--- a/tests/functional/flakes/config.sh
+++ b/tests/functional/flakes/config.sh
@@ -28,6 +28,7 @@ EOF
 # Without --accept-flake-config, the post hook should not run.
 nix build < /dev/null
 (! [[ -f post-hook-ran ]])
+TODO_NixOS
 clearStore
 
 nix build --accept-flake-config
diff --git a/tests/functional/flakes/develop.sh b/tests/functional/flakes/develop.sh
index 83be2e308..60abf3ef2 100755
--- a/tests/functional/flakes/develop.sh
+++ b/tests/functional/flakes/develop.sh
@@ -2,6 +2,8 @@
 
 source ../common.sh
 
+TODO_NixOS
+
 clearStore
 rm -rf $TEST_HOME/.cache $TEST_HOME/.config $TEST_HOME/.local
 
diff --git a/tests/functional/flakes/flake-in-submodule.sh b/tests/functional/flakes/flake-in-submodule.sh
index 08f751216..817f77783 100755
--- a/tests/functional/flakes/flake-in-submodule.sh
+++ b/tests/functional/flakes/flake-in-submodule.sh
@@ -15,6 +15,8 @@ source common.sh
 
 requireGit
 
+TODO_NixOS
+
 clearStore
 
 # Submodules can't be fetched locally by default.
diff --git a/tests/functional/flakes/flakes.sh b/tests/functional/flakes/flakes.sh
index 3057c0293..9d2524d15 100755
--- a/tests/functional/flakes/flakes.sh
+++ b/tests/functional/flakes/flakes.sh
@@ -2,6 +2,8 @@
 
 source ./common.sh
 
+TODO_NixOS
+
 requireGit
 
 clearStore
diff --git a/tests/functional/flakes/run.sh b/tests/functional/flakes/run.sh
index 4d8b512b9..c2c345ed2 100755
--- a/tests/functional/flakes/run.sh
+++ b/tests/functional/flakes/run.sh
@@ -2,6 +2,8 @@
 
 source ../common.sh
 
+TODO_NixOS
+
 clearStore
 rm -rf $TEST_HOME/.cache $TEST_HOME/.config $TEST_HOME/.local
 cp ../shell-hello.nix ../config.nix $TEST_HOME
diff --git a/tests/functional/flakes/search-root.sh b/tests/functional/flakes/search-root.sh
index 600dcf937..c61ae3bfa 100755
--- a/tests/functional/flakes/search-root.sh
+++ b/tests/functional/flakes/search-root.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 writeSimpleFlake "$TEST_HOME"
diff --git a/tests/functional/fmt.sh b/tests/functional/fmt.sh
index 8fc9a3979..114aba396 100755
--- a/tests/functional/fmt.sh
+++ b/tests/functional/fmt.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 rm -rf $TEST_HOME/.cache $TEST_HOME/.config $TEST_HOME/.local
 
diff --git a/tests/functional/gc-auto.sh b/tests/functional/gc-auto.sh
index 98bb7e60e..8f25be3e9 100755
--- a/tests/functional/gc-auto.sh
+++ b/tests/functional/gc-auto.sh
@@ -4,6 +4,8 @@ source common.sh
 
 needLocalStore "“min-free” and “max-free” are daemon options"
 
+TODO_NixOS
+
 clearStore
 
 garbage1=$(nix store add-path --name garbage1 ./nar-access.sh)
diff --git a/tests/functional/gc-concurrent.sh b/tests/functional/gc-concurrent.sh
index 128271287..df180b14f 100755
--- a/tests/functional/gc-concurrent.sh
+++ b/tests/functional/gc-concurrent.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 lockFifo1=$TEST_ROOT/test1.fifo
diff --git a/tests/functional/gc-non-blocking.sh b/tests/functional/gc-non-blocking.sh
index ecfa421fb..de10837eb 100755
--- a/tests/functional/gc-non-blocking.sh
+++ b/tests/functional/gc-non-blocking.sh
@@ -4,6 +4,8 @@
 # parallel with it.
 source common.sh
 
+TODO_NixOS
+
 needLocalStore "the GC test needs a synchronisation point"
 
 clearStore
diff --git a/tests/functional/gc-runtime.sh b/tests/functional/gc-runtime.sh
index b5f6f769c..0cccaaf16 100755
--- a/tests/functional/gc-runtime.sh
+++ b/tests/functional/gc-runtime.sh
@@ -11,6 +11,8 @@ esac
 
 set -m # enable job control, needed for kill
 
+TODO_NixOS
+
 profiles="$NIX_STATE_DIR"/profiles
 rm -rf "$profiles"
 
diff --git a/tests/functional/gc.sh b/tests/functional/gc.sh
index 7594312bb..7707a7e27 100755
--- a/tests/functional/gc.sh
+++ b/tests/functional/gc.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 drvPath=$(nix-instantiate dependencies.nix)
diff --git a/tests/functional/git-hashing/common.sh b/tests/functional/git-hashing/common.sh
index 572cea438..639da16ce 100644
--- a/tests/functional/git-hashing/common.sh
+++ b/tests/functional/git-hashing/common.sh
@@ -1,5 +1,7 @@
 source ../common.sh
 
+TODO_NixOS
+
 clearStore
 clearCache
 
diff --git a/tests/functional/help.sh b/tests/functional/help.sh
index 6436fb500..1bb8e9f9f 100755
--- a/tests/functional/help.sh
+++ b/tests/functional/help.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 # test help output
diff --git a/tests/functional/import-derivation.sh b/tests/functional/import-derivation.sh
index 96cc30646..be28b1604 100755
--- a/tests/functional/import-derivation.sh
+++ b/tests/functional/import-derivation.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 if nix-instantiate --readonly-mode ./import-derivation.nix; then
diff --git a/tests/functional/impure-derivations.sh b/tests/functional/impure-derivations.sh
index b59f73c77..475dba732 100755
--- a/tests/functional/impure-derivations.sh
+++ b/tests/functional/impure-derivations.sh
@@ -4,6 +4,8 @@ source common.sh
 
 requireDaemonNewerThan "2.8pre20220311"
 
+TODO_NixOS
+
 enableFeatures "ca-derivations impure-derivations"
 restartDaemon
 
diff --git a/tests/functional/impure-env.sh b/tests/functional/impure-env.sh
index e65c78b00..ca32c1030 100755
--- a/tests/functional/impure-env.sh
+++ b/tests/functional/impure-env.sh
@@ -5,6 +5,8 @@ source common.sh
 # Needs the config option 'impure-env' to work
 requireDaemonNewerThan "2.19.0"
 
+TODO_NixOS
+
 enableFeatures "configurable-impure-env"
 restartDaemon
 
diff --git a/tests/functional/linux-sandbox.sh b/tests/functional/linux-sandbox.sh
index e71224f5e..653a3873f 100755
--- a/tests/functional/linux-sandbox.sh
+++ b/tests/functional/linux-sandbox.sh
@@ -4,6 +4,8 @@ source common.sh
 
 needLocalStore "the sandbox only runs on the builder side, so it makes no sense to test it with the daemon"
 
+TODO_NixOS
+
 clearStore
 
 requireSandboxSupport
diff --git a/tests/functional/local-overlay-store/bad-uris.sh b/tests/functional/local-overlay-store/bad-uris.sh
index 42a6d47f7..b7930e32e 100644
--- a/tests/functional/local-overlay-store/bad-uris.sh
+++ b/tests/functional/local-overlay-store/bad-uris.sh
@@ -15,6 +15,8 @@ declare -a storesBad=(
     "$storeBadRoot" "$storeBadLower" "$storeBadUpper"
 )
 
+TODO_NixOS
+
 for i in "${storesBad[@]}"; do
     echo $i
     unshare --mount --map-root-user bash <<EOF
diff --git a/tests/functional/local-overlay-store/common.sh b/tests/functional/local-overlay-store/common.sh
index bbe84847a..b171f91f4 100644
--- a/tests/functional/local-overlay-store/common.sh
+++ b/tests/functional/local-overlay-store/common.sh
@@ -1,5 +1,7 @@
 source ../common/vars-and-functions.sh
 
+TODO_NixOS
+
 # The new Linux mount interface does not seem to support remounting
 # OverlayFS mount points.
 #
diff --git a/tests/functional/logging.sh b/tests/functional/logging.sh
index 63752f6db..bd80a9163 100755
--- a/tests/functional/logging.sh
+++ b/tests/functional/logging.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 path=$(nix-build dependencies.nix --no-out-link)
diff --git a/tests/functional/multiple-outputs.sh b/tests/functional/multiple-outputs.sh
index 31ce2a3a4..c4af56f0b 100755
--- a/tests/functional/multiple-outputs.sh
+++ b/tests/functional/multiple-outputs.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 rm -f $TEST_ROOT/result*
diff --git a/tests/functional/nar-access.sh b/tests/functional/nar-access.sh
index 8839fd043..b254081cf 100755
--- a/tests/functional/nar-access.sh
+++ b/tests/functional/nar-access.sh
@@ -27,6 +27,8 @@ diff -u baz.cat-nar $storePath/foo/baz
 nix store cat $storePath/foo/baz > baz.cat-nar
 diff -u baz.cat-nar $storePath/foo/baz
 
+TODO_NixOS
+
 # Check that 'nix store cat' fails on invalid store paths.
 invalidPath="$(dirname $storePath)/99999999999999999999999999999999-foo"
 cp -r $storePath $invalidPath
diff --git a/tests/functional/nested-sandboxing.sh b/tests/functional/nested-sandboxing.sh
index 44c3bb2bc..ae0256de2 100755
--- a/tests/functional/nested-sandboxing.sh
+++ b/tests/functional/nested-sandboxing.sh
@@ -4,6 +4,8 @@ source common.sh
 # This test is run by `tests/functional/nested-sandboxing/runner.nix` in an extra layer of sandboxing.
 [[ -d /nix/store ]] || skipTest "running this test without Nix's deps being drawn from /nix/store is not yet supported"
 
+TODO_NixOS
+
 requireSandboxSupport
 
 source ./nested-sandboxing/command.sh
diff --git a/tests/functional/nix-build.sh b/tests/functional/nix-build.sh
index 45ff314c7..cfba7f020 100755
--- a/tests/functional/nix-build.sh
+++ b/tests/functional/nix-build.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 outPath=$(nix-build dependencies.nix -o $TEST_ROOT/result)
diff --git a/tests/functional/nix-collect-garbage-d.sh b/tests/functional/nix-collect-garbage-d.sh
index 07aaf61e9..119efe629 100755
--- a/tests/functional/nix-collect-garbage-d.sh
+++ b/tests/functional/nix-collect-garbage-d.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 ## Test `nix-collect-garbage -d`
diff --git a/tests/functional/nix-copy-ssh-common.sh b/tests/functional/nix-copy-ssh-common.sh
index cc8314ff7..5eea9612d 100644
--- a/tests/functional/nix-copy-ssh-common.sh
+++ b/tests/functional/nix-copy-ssh-common.sh
@@ -2,6 +2,8 @@ proto=$1
 shift
 (( $# == 0 ))
 
+TODO_NixOS
+
 clearStore
 clearCache
 
diff --git a/tests/functional/nix-copy-ssh-ng.sh b/tests/functional/nix-copy-ssh-ng.sh
index 1fd735b9d..41958c2c3 100755
--- a/tests/functional/nix-copy-ssh-ng.sh
+++ b/tests/functional/nix-copy-ssh-ng.sh
@@ -4,6 +4,8 @@ source common.sh
 
 source nix-copy-ssh-common.sh "ssh-ng"
 
+TODO_NixOS
+
 clearStore
 clearRemoteStore
 
diff --git a/tests/functional/nix-profile.sh b/tests/functional/nix-profile.sh
index 3e5846cf2..e2f19b99e 100755
--- a/tests/functional/nix-profile.sh
+++ b/tests/functional/nix-profile.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 clearProfiles
 
diff --git a/tests/functional/nix-shell.sh b/tests/functional/nix-shell.sh
index c38107e64..66aece388 100755
--- a/tests/functional/nix-shell.sh
+++ b/tests/functional/nix-shell.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 if [[ -n ${CONTENT_ADDRESSED:-} ]]; then
diff --git a/tests/functional/optimise-store.sh b/tests/functional/optimise-store.sh
index 70ce954f9..f010c5549 100755
--- a/tests/functional/optimise-store.sh
+++ b/tests/functional/optimise-store.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 outPath1=$(echo 'with import ./config.nix; mkDerivation { name = "foo1"; builder = builtins.toFile "builder" "mkdir $out; echo hello > $out/foo"; }' | nix-build - --no-out-link --auto-optimise-store)
diff --git a/tests/functional/output-normalization.sh b/tests/functional/output-normalization.sh
index 2b319201a..c55f1b1d1 100755
--- a/tests/functional/output-normalization.sh
+++ b/tests/functional/output-normalization.sh
@@ -3,6 +3,7 @@
 source common.sh
 
 testNormalization () {
+    TODO_NixOS
     clearStore
     outPath=$(nix-build ./simple.nix --no-out-link)
     test "$(stat -c %Y $outPath)" -eq 1
diff --git a/tests/functional/parallel.sh b/tests/functional/parallel.sh
index 3b7bbe5a2..7e420688d 100644
--- a/tests/functional/parallel.sh
+++ b/tests/functional/parallel.sh
@@ -4,6 +4,8 @@ source common.sh
 # First, test that -jN performs builds in parallel.
 echo "testing nix-build -j..."
 
+TODO_NixOS
+
 clearStore
 
 rm -f $_NIX_TEST_SHARED.cur $_NIX_TEST_SHARED.max
diff --git a/tests/functional/pass-as-file.sh b/tests/functional/pass-as-file.sh
index 21d9ffc6d..0b5605d05 100755
--- a/tests/functional/pass-as-file.sh
+++ b/tests/functional/pass-as-file.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 outPath=$(nix-build --no-out-link -E "
diff --git a/tests/functional/placeholders.sh b/tests/functional/placeholders.sh
index f2b8bf6bf..d4e09a91b 100755
--- a/tests/functional/placeholders.sh
+++ b/tests/functional/placeholders.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 nix-build --no-out-link -E '
diff --git a/tests/functional/post-hook.sh b/tests/functional/post-hook.sh
index 7540d1045..94a6d0d69 100755
--- a/tests/functional/post-hook.sh
+++ b/tests/functional/post-hook.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 rm -f $TEST_ROOT/result
diff --git a/tests/functional/pure-eval.sh b/tests/functional/pure-eval.sh
index 6d8aa35ec..8a18dec6e 100755
--- a/tests/functional/pure-eval.sh
+++ b/tests/functional/pure-eval.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 nix eval --expr 'assert 1 + 2 == 3; true'
diff --git a/tests/functional/read-only-store.sh b/tests/functional/read-only-store.sh
index ecc57642d..f6b6eaf32 100755
--- a/tests/functional/read-only-store.sh
+++ b/tests/functional/read-only-store.sh
@@ -6,6 +6,8 @@ enableFeatures "read-only-local-store"
 
 needLocalStore "cannot open store read-only when daemon has already opened it writeable"
 
+TODO_NixOS
+
 clearStore
 
 happy () {
diff --git a/tests/functional/readfile-context.sh b/tests/functional/readfile-context.sh
index d0644471d..0ef549c8d 100755
--- a/tests/functional/readfile-context.sh
+++ b/tests/functional/readfile-context.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 outPath=$(nix-build --no-out-link readfile-context.nix)
diff --git a/tests/functional/recursive.sh b/tests/functional/recursive.sh
index a9966aabd..6b255e81a 100755
--- a/tests/functional/recursive.sh
+++ b/tests/functional/recursive.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 enableFeatures 'recursive-nix'
 restartDaemon
 
diff --git a/tests/functional/referrers.sh b/tests/functional/referrers.sh
index 0fda97378..411cdb7c1 100755
--- a/tests/functional/referrers.sh
+++ b/tests/functional/referrers.sh
@@ -4,6 +4,8 @@ source common.sh
 
 needLocalStore "uses some low-level store manipulations that aren’t available through the daemon"
 
+TODO_NixOS
+
 clearStore
 
 max=500
diff --git a/tests/functional/remote-store.sh b/tests/functional/remote-store.sh
index 171a5d391..841b6b27a 100755
--- a/tests/functional/remote-store.sh
+++ b/tests/functional/remote-store.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 # Ensure "fake ssh" remote store works just as legacy fake ssh would.
diff --git a/tests/functional/repair.sh b/tests/functional/repair.sh
index 552e04280..1f6004b2c 100755
--- a/tests/functional/repair.sh
+++ b/tests/functional/repair.sh
@@ -4,6 +4,8 @@ source common.sh
 
 needLocalStore "--repair needs a local store"
 
+TODO_NixOS
+
 clearStore
 
 path=$(nix-build dependencies.nix -o $TEST_ROOT/result)
diff --git a/tests/functional/repl.sh b/tests/functional/repl.sh
index fca982807..86cd6f458 100755
--- a/tests/functional/repl.sh
+++ b/tests/functional/repl.sh
@@ -22,6 +22,8 @@ replUndefinedVariable="
 import $testDir/undefined-variable.nix
 "
 
+TODO_NixOS
+
 testRepl () {
     local nixArgs
     nixArgs=("$@")
diff --git a/tests/functional/restricted.sh b/tests/functional/restricted.sh
index ab4cad5cf..917a554c5 100755
--- a/tests/functional/restricted.sh
+++ b/tests/functional/restricted.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 nix-instantiate --restrict-eval --eval -E '1 + 2'
diff --git a/tests/functional/search.sh b/tests/functional/search.sh
index ce17411d2..1195c2a06 100755
--- a/tests/functional/search.sh
+++ b/tests/functional/search.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 clearCache
 
diff --git a/tests/functional/secure-drv-outputs.sh b/tests/functional/secure-drv-outputs.sh
index 7d81db58b..5cc4af435 100755
--- a/tests/functional/secure-drv-outputs.sh
+++ b/tests/functional/secure-drv-outputs.sh
@@ -6,6 +6,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 startDaemon
diff --git a/tests/functional/selfref-gc.sh b/tests/functional/selfref-gc.sh
index 37ce33089..a5e368b51 100755
--- a/tests/functional/selfref-gc.sh
+++ b/tests/functional/selfref-gc.sh
@@ -4,6 +4,8 @@ source common.sh
 
 requireDaemonNewerThan "2.6.0pre20211215"
 
+TODO_NixOS
+
 clearStore
 
 nix-build --no-out-link -E '
diff --git a/tests/functional/shell.sh b/tests/functional/shell.sh
index 1760eefff..b4c03f547 100755
--- a/tests/functional/shell.sh
+++ b/tests/functional/shell.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 clearCache
 
diff --git a/tests/functional/signing.sh b/tests/functional/signing.sh
index cf84ab377..d268fd116 100755
--- a/tests/functional/signing.sh
+++ b/tests/functional/signing.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 clearCache
 
diff --git a/tests/functional/simple.sh b/tests/functional/simple.sh
index 4e7d37f59..86acca0c2 100755
--- a/tests/functional/simple.sh
+++ b/tests/functional/simple.sh
@@ -17,6 +17,8 @@ echo "output path is $outPath"
 text=$(cat "$outPath/hello")
 if test "$text" != "Hello World!"; then exit 1; fi
 
+TODO_NixOS
+
 # Directed delete: $outPath is not reachable from a root, so it should
 # be deleteable.
 nix-store --delete $outPath
diff --git a/tests/functional/store-info.sh b/tests/functional/store-info.sh
index 2398f5beb..f37889fbb 100755
--- a/tests/functional/store-info.sh
+++ b/tests/functional/store-info.sh
@@ -16,4 +16,6 @@ fi
 expect 127 NIX_REMOTE=unix:$PWD/store nix store info || \
     fail "nix store info on a non-existent store should fail"
 
+TODO_NixOS
+
 [[ "$(echo "$STORE_INFO_JSON" | jq -r ".url")" == "${NIX_REMOTE:-local}" ]]
diff --git a/tests/functional/structured-attrs.sh b/tests/functional/structured-attrs.sh
index ba7f5967e..32d4c9957 100755
--- a/tests/functional/structured-attrs.sh
+++ b/tests/functional/structured-attrs.sh
@@ -6,6 +6,8 @@ source common.sh
 # tests for the older versions
 requireDaemonNewerThan "2.4pre20210712"
 
+TODO_NixOS
+
 clearStore
 
 rm -f $TEST_ROOT/result
diff --git a/tests/functional/suggestions.sh b/tests/functional/suggestions.sh
index 6ec1cd322..1140e4f78 100755
--- a/tests/functional/suggestions.sh
+++ b/tests/functional/suggestions.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 cd "$TEST_HOME"
diff --git a/tests/functional/supplementary-groups.sh b/tests/functional/supplementary-groups.sh
index 9d474219f..5d329efc9 100755
--- a/tests/functional/supplementary-groups.sh
+++ b/tests/functional/supplementary-groups.sh
@@ -7,6 +7,8 @@ requireSandboxSupport
 if ! command -p -v unshare; then skipTest "Need unshare"; fi
 needLocalStore "The test uses --store always so we would just be bypassing the daemon"
 
+TODO_NixOS
+
 unshare --mount --map-root-user bash <<EOF
   source common.sh
 
diff --git a/tests/functional/tarball.sh b/tests/functional/tarball.sh
index ce162ddce..eb541f3bb 100755
--- a/tests/functional/tarball.sh
+++ b/tests/functional/tarball.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 rm -rf $TEST_HOME
diff --git a/tests/functional/user-envs-migration.sh b/tests/functional/user-envs-migration.sh
index 992586b95..0f33074e1 100755
--- a/tests/functional/user-envs-migration.sh
+++ b/tests/functional/user-envs-migration.sh
@@ -13,6 +13,8 @@ fi
 killDaemon
 unset NIX_REMOTE
 
+TODO_NixOS
+
 clearStore
 clearProfiles
 rm -rf ~/.nix-profile
diff --git a/tests/functional/user-envs-test-case.sh b/tests/functional/user-envs-test-case.sh
index f4a90a675..117c6c7a4 100644
--- a/tests/functional/user-envs-test-case.sh
+++ b/tests/functional/user-envs-test-case.sh
@@ -11,6 +11,8 @@ outPath10=$(nix-env -f ./user-envs.nix -qa --out-path --no-name '*' | grep foo-1
 drvPath10=$(nix-env -f ./user-envs.nix -qa --drv-path --no-name '*' | grep foo-1.0)
 [ -n "$outPath10" -a -n "$drvPath10" ]
 
+TODO_NixOS
+
 # Query with json
 nix-env -f ./user-envs.nix -qa --json | jq -e '.[] | select(.name == "bar-0.1") | [
     .outputName == "out",
diff --git a/tests/functional/why-depends.sh b/tests/functional/why-depends.sh
index 69b365069..1ce66f154 100755
--- a/tests/functional/why-depends.sh
+++ b/tests/functional/why-depends.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 
 cp ./dependencies.nix ./dependencies.builder0.sh ./config.nix $TEST_HOME
diff --git a/tests/functional/zstd.sh b/tests/functional/zstd.sh
index 3bf9d5601..90fe58539 100755
--- a/tests/functional/zstd.sh
+++ b/tests/functional/zstd.sh
@@ -2,6 +2,8 @@
 
 source common.sh
 
+TODO_NixOS
+
 clearStore
 clearCache