diff --git a/.github/workflows/CICD.yml b/.github/workflows/CICD.yml
index 07c768afd..d2f6f5726 100644
--- a/.github/workflows/CICD.yml
+++ b/.github/workflows/CICD.yml
@@ -138,20 +138,6 @@ jobs:
         # * convert any errors/warnings to GHA UI annotations; ref: <https://help.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-a-warning-message>
         S=$(cargo fmt -- --check) && printf "%s\n" "$S" || { printf "%s\n" "$S" ; printf "%s\n" "$S" | sed -E -n -e "s/^Diff[[:space:]]+in[[:space:]]+${PWD//\//\\/}\/(.*)[[:space:]]+at[[:space:]]+[^0-9]+([0-9]+).*$/::${fault_type} file=\1,line=\2::${fault_prefix}: \`cargo fmt\`: style violation (file:'\1', line:\2; use \`cargo fmt -- \"\1\"\`)/p" ; fault=true ; }
         if [ -n "${{ steps.vars.outputs.FAIL_ON_FAULT }}" ] && [ -n "$fault" ]; then exit 1 ; fi
-    - name: "`cargo fmt` testing of integration tests"
-      if: success() || failure() # run regardless of prior step success/failure
-      shell: bash
-      run: |
-        ## `cargo fmt` testing of integration tests
-        unset fault
-        fault_type="${{ steps.vars.outputs.FAULT_TYPE }}"
-        fault_prefix=$(echo "$fault_type" | tr '[:lower:]' '[:upper:]')
-        # 'tests' is the standard/usual integration test directory
-        if [ -d tests ]; then
-          # * convert any errors/warnings to GHA UI annotations; ref: <https://help.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-a-warning-message>
-          S=$(find tests -name "*.rs" -print0 | xargs -0 cargo fmt -- --check) && printf "%s\n" "$S" || { printf "%s\n" "$S" ; printf "%s\n" "$S" | sed -E -n "s/^Diff[[:space:]]+in[[:space:]]+${PWD//\//\\/}\/(.*)[[:space:]]+at[[:space:]]+[^0-9]+([0-9]+).*$/::${fault_type} file=\1,line=\2::${fault_prefix}: \`cargo fmt\`: style violation (file:'\1', line:\2; use \`cargo fmt \"\1\"\`)/p" ; fault=true ; }
-        fi
-        if [ -n "${{ steps.vars.outputs.FAIL_ON_FAULT }}" ] && [ -n "$fault" ]; then exit 1 ; fi
 
   style_lint:
     name: Style/lint
diff --git a/build.rs b/build.rs
index 734dfc350..c9f07259a 100644
--- a/build.rs
+++ b/build.rs
@@ -18,10 +18,6 @@ pub fn main() {
 
     let out_dir = env::var("OUT_DIR").unwrap();
     // println!("cargo:warning=out_dir={}", out_dir);
-    let manifest_dir = env::var("CARGO_MANIFEST_DIR").unwrap().replace('\\', "/");
-    // println!("cargo:warning=manifest_dir={}", manifest_dir);
-    let util_tests_dir = format!("{}/tests/by-util", manifest_dir);
-    // println!("cargo:warning=util_tests_dir={}", util_tests_dir);
 
     let mut crates = Vec::new();
     for (key, val) in env::vars() {
@@ -41,7 +37,6 @@ pub fn main() {
     crates.sort();
 
     let mut mf = File::create(Path::new(&out_dir).join("uutils_map.rs")).unwrap();
-    let mut tf = File::create(Path::new(&out_dir).join("test_modules.rs")).unwrap();
 
     mf.write_all(
         "type UtilityMap<T> = phf::Map<&'static str, (fn(T) -> i32, fn() -> Command<'static>)>;\n\
@@ -60,42 +55,15 @@ pub fn main() {
             "uu_test" => {
                 phf_map.entry("test", &map_value);
                 phf_map.entry("[", &map_value);
-
-                tf.write_all(
-                    format!(
-                        "#[path=\"{dir}/test_test.rs\"]\nmod test_test;\n",
-                        dir = util_tests_dir,
-                    )
-                    .as_bytes(),
-                )
-                .unwrap();
             }
             k if k.starts_with(OVERRIDE_PREFIX) => {
                 phf_map.entry(&k[OVERRIDE_PREFIX.len()..], &map_value);
-                tf.write_all(
-                    format!(
-                        "#[path=\"{dir}/test_{k}.rs\"]\nmod test_{k};\n",
-                        k = &krate[OVERRIDE_PREFIX.len()..],
-                        dir = util_tests_dir,
-                    )
-                    .as_bytes(),
-                )
-                .unwrap();
             }
             "false" | "true" => {
                 phf_map.entry(
                     krate,
                     &format!("(r#{krate}::uumain, r#{krate}::uu_app)", krate = krate),
                 );
-                tf.write_all(
-                    format!(
-                        "#[path=\"{dir}/test_{krate}.rs\"]\nmod test_{krate};\n",
-                        krate = krate,
-                        dir = util_tests_dir,
-                    )
-                    .as_bytes(),
-                )
-                .unwrap();
             }
             "hashsum" => {
                 phf_map.entry(
@@ -123,27 +91,9 @@ pub fn main() {
                 phf_map.entry("shake256sum", &map_value_bits);
                 phf_map.entry("b2sum", &map_value);
                 phf_map.entry("b3sum", &map_value_b3sum);
-                tf.write_all(
-                    format!(
-                        "#[path=\"{dir}/test_{krate}.rs\"]\nmod test_{krate};\n",
-                        krate = krate,
-                        dir = util_tests_dir,
-                    )
-                    .as_bytes(),
-                )
-                .unwrap();
             }
             _ => {
                 phf_map.entry(krate, &map_value);
-                tf.write_all(
-                    format!(
-                        "#[path=\"{dir}/test_{krate}.rs\"]\nmod test_{krate};\n",
-                        krate = krate,
-                        dir = util_tests_dir,
-                    )
-                    .as_bytes(),
-                )
-                .unwrap();
             }
         }
     }
@@ -151,5 +101,4 @@ pub fn main() {
     mf.write_all(b"\n}\n").unwrap();
 
     mf.flush().unwrap();
-    tf.flush().unwrap();
 }
diff --git a/tests/tests.rs b/tests/tests.rs
index 51c6f6b11..17581799d 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -4,4 +4,414 @@ mod common;
 #[cfg(unix)]
 extern crate rust_users;
 
-include!(concat!(env!("OUT_DIR"), "/test_modules.rs"));
+#[cfg(feature = "arch")]
+#[path = "by-util/test_arch.rs"]
+mod test_arch;
+
+#[cfg(feature = "base32")]
+#[path = "by-util/test_base32.rs"]
+mod test_base32;
+
+#[cfg(feature = "base64")]
+#[path = "by-util/test_base64.rs"]
+mod test_base64;
+
+#[cfg(feature = "basename")]
+#[path = "by-util/test_basename.rs"]
+mod test_basename;
+
+#[cfg(feature = "basenc")]
+#[path = "by-util/test_basenc.rs"]
+mod test_basenc;
+
+#[cfg(feature = "cat")]
+#[path = "by-util/test_cat.rs"]
+mod test_cat;
+
+#[cfg(feature = "chcon")]
+#[path = "by-util/test_chcon.rs"]
+mod test_chcon;
+
+#[cfg(feature = "chgrp")]
+#[path = "by-util/test_chgrp.rs"]
+mod test_chgrp;
+
+#[cfg(feature = "chmod")]
+#[path = "by-util/test_chmod.rs"]
+mod test_chmod;
+
+#[cfg(feature = "chown")]
+#[path = "by-util/test_chown.rs"]
+mod test_chown;
+
+#[cfg(feature = "chroot")]
+#[path = "by-util/test_chroot.rs"]
+mod test_chroot;
+
+#[cfg(feature = "cksum")]
+#[path = "by-util/test_cksum.rs"]
+mod test_cksum;
+
+#[cfg(feature = "comm")]
+#[path = "by-util/test_comm.rs"]
+mod test_comm;
+
+#[cfg(feature = "cp")]
+#[path = "by-util/test_cp.rs"]
+mod test_cp;
+
+#[cfg(feature = "csplit")]
+#[path = "by-util/test_csplit.rs"]
+mod test_csplit;
+
+#[cfg(feature = "cut")]
+#[path = "by-util/test_cut.rs"]
+mod test_cut;
+
+#[cfg(feature = "date")]
+#[path = "by-util/test_date.rs"]
+mod test_date;
+
+#[cfg(feature = "dd")]
+#[path = "by-util/test_dd.rs"]
+mod test_dd;
+
+#[cfg(feature = "df")]
+#[path = "by-util/test_df.rs"]
+mod test_df;
+
+#[cfg(feature = "dir")]
+#[path = "by-util/test_dir.rs"]
+mod test_dir;
+
+#[cfg(feature = "dircolors")]
+#[path = "by-util/test_dircolors.rs"]
+mod test_dircolors;
+
+#[cfg(feature = "dirname")]
+#[path = "by-util/test_dirname.rs"]
+mod test_dirname;
+
+#[cfg(feature = "du")]
+#[path = "by-util/test_du.rs"]
+mod test_du;
+
+#[cfg(feature = "echo")]
+#[path = "by-util/test_echo.rs"]
+mod test_echo;
+
+#[cfg(feature = "env")]
+#[path = "by-util/test_env.rs"]
+mod test_env;
+
+#[cfg(feature = "expand")]
+#[path = "by-util/test_expand.rs"]
+mod test_expand;
+
+#[cfg(feature = "expr")]
+#[path = "by-util/test_expr.rs"]
+mod test_expr;
+
+#[cfg(feature = "factor")]
+#[path = "by-util/test_factor.rs"]
+mod test_factor;
+
+#[cfg(feature = "false")]
+#[path = "by-util/test_false.rs"]
+mod test_false;
+
+#[cfg(feature = "fmt")]
+#[path = "by-util/test_fmt.rs"]
+mod test_fmt;
+
+#[cfg(feature = "fold")]
+#[path = "by-util/test_fold.rs"]
+mod test_fold;
+
+#[cfg(feature = "groups")]
+#[path = "by-util/test_groups.rs"]
+mod test_groups;
+
+#[cfg(feature = "hashsum")]
+#[path = "by-util/test_hashsum.rs"]
+mod test_hashsum;
+
+#[cfg(feature = "head")]
+#[path = "by-util/test_head.rs"]
+mod test_head;
+
+#[cfg(feature = "hostid")]
+#[path = "by-util/test_hostid.rs"]
+mod test_hostid;
+
+#[cfg(feature = "hostname")]
+#[path = "by-util/test_hostname.rs"]
+mod test_hostname;
+
+#[cfg(feature = "id")]
+#[path = "by-util/test_id.rs"]
+mod test_id;
+
+#[cfg(feature = "install")]
+#[path = "by-util/test_install.rs"]
+mod test_install;
+
+#[cfg(feature = "join")]
+#[path = "by-util/test_join.rs"]
+mod test_join;
+
+#[cfg(feature = "kill")]
+#[path = "by-util/test_kill.rs"]
+mod test_kill;
+
+#[cfg(feature = "link")]
+#[path = "by-util/test_link.rs"]
+mod test_link;
+
+#[cfg(feature = "ln")]
+#[path = "by-util/test_ln.rs"]
+mod test_ln;
+
+#[cfg(feature = "logname")]
+#[path = "by-util/test_logname.rs"]
+mod test_logname;
+
+#[cfg(feature = "ls")]
+#[path = "by-util/test_ls.rs"]
+mod test_ls;
+
+#[cfg(feature = "mkdir")]
+#[path = "by-util/test_mkdir.rs"]
+mod test_mkdir;
+
+#[cfg(feature = "mkfifo")]
+#[path = "by-util/test_mkfifo.rs"]
+mod test_mkfifo;
+
+#[cfg(feature = "mknod")]
+#[path = "by-util/test_mknod.rs"]
+mod test_mknod;
+
+#[cfg(feature = "mktemp")]
+#[path = "by-util/test_mktemp.rs"]
+mod test_mktemp;
+
+#[cfg(feature = "more")]
+#[path = "by-util/test_more.rs"]
+mod test_more;
+
+#[cfg(feature = "mv")]
+#[path = "by-util/test_mv.rs"]
+mod test_mv;
+
+#[cfg(feature = "nice")]
+#[path = "by-util/test_nice.rs"]
+mod test_nice;
+
+#[cfg(feature = "nl")]
+#[path = "by-util/test_nl.rs"]
+mod test_nl;
+
+#[cfg(feature = "nohup")]
+#[path = "by-util/test_nohup.rs"]
+mod test_nohup;
+
+#[cfg(feature = "nproc")]
+#[path = "by-util/test_nproc.rs"]
+mod test_nproc;
+
+#[cfg(feature = "numfmt")]
+#[path = "by-util/test_numfmt.rs"]
+mod test_numfmt;
+
+#[cfg(feature = "od")]
+#[path = "by-util/test_od.rs"]
+mod test_od;
+
+#[cfg(feature = "paste")]
+#[path = "by-util/test_paste.rs"]
+mod test_paste;
+
+#[cfg(feature = "pathchk")]
+#[path = "by-util/test_pathchk.rs"]
+mod test_pathchk;
+
+#[cfg(feature = "pinky")]
+#[path = "by-util/test_pinky.rs"]
+mod test_pinky;
+
+#[cfg(feature = "pr")]
+#[path = "by-util/test_pr.rs"]
+mod test_pr;
+
+#[cfg(feature = "printenv")]
+#[path = "by-util/test_printenv.rs"]
+mod test_printenv;
+
+#[cfg(feature = "printf")]
+#[path = "by-util/test_printf.rs"]
+mod test_printf;
+
+#[cfg(feature = "ptx")]
+#[path = "by-util/test_ptx.rs"]
+mod test_ptx;
+
+#[cfg(feature = "pwd")]
+#[path = "by-util/test_pwd.rs"]
+mod test_pwd;
+
+#[cfg(feature = "readlink")]
+#[path = "by-util/test_readlink.rs"]
+mod test_readlink;
+
+#[cfg(feature = "realpath")]
+#[path = "by-util/test_realpath.rs"]
+mod test_realpath;
+
+#[cfg(feature = "relpath")]
+#[path = "by-util/test_relpath.rs"]
+mod test_relpath;
+
+#[cfg(feature = "rm")]
+#[path = "by-util/test_rm.rs"]
+mod test_rm;
+
+#[cfg(feature = "rmdir")]
+#[path = "by-util/test_rmdir.rs"]
+mod test_rmdir;
+
+#[cfg(feature = "runcon")]
+#[path = "by-util/test_runcon.rs"]
+mod test_runcon;
+
+#[cfg(feature = "seq")]
+#[path = "by-util/test_seq.rs"]
+mod test_seq;
+
+#[cfg(feature = "shred")]
+#[path = "by-util/test_shred.rs"]
+mod test_shred;
+
+#[cfg(feature = "shuf")]
+#[path = "by-util/test_shuf.rs"]
+mod test_shuf;
+
+#[cfg(feature = "sleep")]
+#[path = "by-util/test_sleep.rs"]
+mod test_sleep;
+
+#[cfg(feature = "sort")]
+#[path = "by-util/test_sort.rs"]
+mod test_sort;
+
+#[cfg(feature = "split")]
+#[path = "by-util/test_split.rs"]
+mod test_split;
+
+#[cfg(feature = "stat")]
+#[path = "by-util/test_stat.rs"]
+mod test_stat;
+
+#[cfg(feature = "stdbuf")]
+#[path = "by-util/test_stdbuf.rs"]
+mod test_stdbuf;
+
+#[cfg(feature = "stty")]
+#[path = "by-util/test_stty.rs"]
+mod test_stty;
+
+#[cfg(feature = "sum")]
+#[path = "by-util/test_sum.rs"]
+mod test_sum;
+
+#[cfg(feature = "sync")]
+#[path = "by-util/test_sync.rs"]
+mod test_sync;
+
+#[cfg(feature = "tac")]
+#[path = "by-util/test_tac.rs"]
+mod test_tac;
+
+#[cfg(feature = "tail")]
+#[path = "by-util/test_tail.rs"]
+mod test_tail;
+
+#[cfg(feature = "tee")]
+#[path = "by-util/test_tee.rs"]
+mod test_tee;
+
+#[cfg(feature = "test")]
+#[path = "by-util/test_test.rs"]
+mod test_test;
+
+#[cfg(feature = "timeout")]
+#[path = "by-util/test_timeout.rs"]
+mod test_timeout;
+
+#[cfg(feature = "touch")]
+#[path = "by-util/test_touch.rs"]
+mod test_touch;
+
+#[cfg(feature = "tr")]
+#[path = "by-util/test_tr.rs"]
+mod test_tr;
+
+#[cfg(feature = "true")]
+#[path = "by-util/test_true.rs"]
+mod test_true;
+
+#[cfg(feature = "truncate")]
+#[path = "by-util/test_truncate.rs"]
+mod test_truncate;
+
+#[cfg(feature = "tsort")]
+#[path = "by-util/test_tsort.rs"]
+mod test_tsort;
+
+#[cfg(feature = "tty")]
+#[path = "by-util/test_tty.rs"]
+mod test_tty;
+
+#[cfg(feature = "uname")]
+#[path = "by-util/test_uname.rs"]
+mod test_uname;
+
+#[cfg(feature = "unexpand")]
+#[path = "by-util/test_unexpand.rs"]
+mod test_unexpand;
+
+#[cfg(feature = "uniq")]
+#[path = "by-util/test_uniq.rs"]
+mod test_uniq;
+
+#[cfg(feature = "unlink")]
+#[path = "by-util/test_unlink.rs"]
+mod test_unlink;
+
+#[cfg(feature = "uptime")]
+#[path = "by-util/test_uptime.rs"]
+mod test_uptime;
+
+#[cfg(feature = "users")]
+#[path = "by-util/test_users.rs"]
+mod test_users;
+
+#[cfg(feature = "vdir")]
+#[path = "by-util/test_vdir.rs"]
+mod test_vdir;
+
+#[cfg(feature = "wc")]
+#[path = "by-util/test_wc.rs"]
+mod test_wc;
+
+#[cfg(feature = "who")]
+#[path = "by-util/test_who.rs"]
+mod test_who;
+
+#[cfg(feature = "whoami")]
+#[path = "by-util/test_whoami.rs"]
+mod test_whoami;
+
+#[cfg(feature = "yes")]
+#[path = "by-util/test_yes.rs"]
+mod test_yes;