diff --git a/.github/workflows/CICD.yml b/.github/workflows/CICD.yml
index f91795cbf..58f9a21e4 100644
--- a/.github/workflows/CICD.yml
+++ b/.github/workflows/CICD.yml
@@ -1079,11 +1079,23 @@ jobs:
         RUSTDOCFLAGS: "-Cpanic=abort"
         # RUSTUP_TOOLCHAIN: ${{ steps.vars.outputs.TOOLCHAIN }}
     - name: "`grcov` ~ install"
-      uses: actions-rs/install@v0.1
-      with:
-        crate: grcov
-        version: latest
-        use-tool-cache: false
+      id: build_grcov
+      shell: bash
+      run: |
+        git clone https://github.com/mozilla/grcov.git ~/grcov/
+        cd ~/grcov
+        # Hardcode the version of crossbeam-epoch. See
+        # https://github.com/uutils/coreutils/issues/3680
+        sed -i -e "s|tempfile =|crossbeam-epoch = \"=0.9.8\"\ntempfile =|" Cargo.toml
+        cargo install --path .
+        cd -
+# Uncomment when the upstream issue
+# https://github.com/mozilla/grcov/issues/849 is fixed
+#      uses: actions-rs/install@v0.1
+#      with:
+#        crate: grcov
+#        version: latest
+#        use-tool-cache: false
     - name: Generate coverage data (via `grcov`)
       id: coverage
       shell: bash
@@ -1095,9 +1107,9 @@ jobs:
         # GRCOV_EXCLUDE_OPTION='--excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()"' ## `grcov` ignores these params when passed as an environment variable (why?)
         mkdir -p "${COVERAGE_REPORT_DIR}"
         # display coverage files
-        grcov . --output-type files --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()" | sort --unique
+        ~/.cargo/bin/grcov . --output-type files --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()" | sort --unique
         # generate coverage report
-        grcov . --output-type lcov --output-path "${COVERAGE_REPORT_FILE}" --branch --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()"
+        ~/.cargo/bin/grcov . --output-type lcov --output-path "${COVERAGE_REPORT_FILE}" --branch --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()"
         echo ::set-output name=report::${COVERAGE_REPORT_FILE}
     - name: Upload coverage results (to Codecov.io)
       uses: codecov/codecov-action@v3
diff --git a/Cargo.lock b/Cargo.lock
index e0413c73c..367360ea6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1280,9 +1280,9 @@ checksum = "b8f8bdf33df195859076e54ab11ee78a1b208382d3a26ec40d142ffc1ecc49ef"
 
 [[package]]
 name = "once_cell"
-version = "1.12.0"
+version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7709cef83f0c1f58f666e746a08b21e0085f7440fa6a29cc194d68aac97a4225"
+checksum = "18a6dbe30758c9f83eb00cbea4ac95966305f5a7772f3f42ebfc7fc7eddbd8e1"
 
 [[package]]
 name = "onig"
diff --git a/src/uu/comm/src/comm.rs b/src/uu/comm/src/comm.rs
index 78ef4e5c2..24d089df4 100644
--- a/src/uu/comm/src/comm.rs
+++ b/src/uu/comm/src/comm.rs
@@ -33,7 +33,10 @@ mod options {
 
 fn mkdelim(col: usize, opts: &ArgMatches) -> String {
     let mut s = String::new();
-    let delim = opts.value_of(options::DELIMITER).unwrap();
+    let delim = match opts.value_of(options::DELIMITER).unwrap() {
+        "" => "\0",
+        delim => delim,
+    };
 
     if col > 1 && !opts.is_present(options::COLUMN_1) {
         s.push_str(delim.as_ref());
diff --git a/src/uu/ls/Cargo.toml b/src/uu/ls/Cargo.toml
index 49254cf8d..f5e461750 100644
--- a/src/uu/ls/Cargo.toml
+++ b/src/uu/ls/Cargo.toml
@@ -24,7 +24,7 @@ termsize = "0.1.6"
 glob = "0.3.0"
 lscolors = { version = "0.10.0", features = ["ansi_term"] }
 uucore = { version = ">=0.0.8", package = "uucore", path = "../../uucore", features = ["entries", "fs"] }
-once_cell = "1.12.0"
+once_cell = "1.13.0"
 atty = "0.2"
 selinux = { version="0.2", optional = true }
 
diff --git a/src/uucore/Cargo.toml b/src/uucore/Cargo.toml
index 961bcbb20..5d86b67a2 100644
--- a/src/uucore/Cargo.toml
+++ b/src/uucore/Cargo.toml
@@ -32,7 +32,7 @@ data-encoding = { version="2.1", optional=true }
 data-encoding-macro = { version="0.1.12", optional=true }
 z85 = { version="3.0.5", optional=true }
 libc = { version="0.2.126", optional=true }
-once_cell = "1.12.0"
+once_cell = "1.13.0"
 os_display = "0.1.3"
 
 [target.'cfg(unix)'.dependencies]
diff --git a/tests/by-util/test_comm.rs b/tests/by-util/test_comm.rs
index ebfc9c6f9..b470f708b 100644
--- a/tests/by-util/test_comm.rs
+++ b/tests/by-util/test_comm.rs
@@ -59,13 +59,12 @@ fn output_delimiter() {
         .stdout_only_fixture("ab_delimiter_word.expected");
 }
 
-#[cfg_attr(not(feature = "test_unimplemented"), ignore)]
 #[test]
-fn output_delimiter_require_arg() {
+fn output_delimiter_nul() {
     new_ucmd!()
         .args(&["--output-delimiter=", "a", "b"])
-        .fails()
-        .stderr_only("error to be defined");
+        .succeeds()
+        .stdout_only_fixture("ab_delimiter_nul.expected");
 }
 
 // even though (info) documentation suggests this is an option
diff --git a/tests/by-util/test_realpath.rs b/tests/by-util/test_realpath.rs
index c469eb0da..6e413ce9e 100644
--- a/tests/by-util/test_realpath.rs
+++ b/tests/by-util/test_realpath.rs
@@ -219,7 +219,7 @@ fn test_realpath_when_symlink_is_absolute_and_enoent() {
     at.mkdir("dir1");
     at.symlink_file("dir2/bar", "dir1/foo1");
     at.symlink_file("/dir2/bar", "dir1/foo2");
-    at.relative_symlink_file("dir2/baz", at.plus("dir1/foo3").to_str().unwrap());
+    at.relative_symlink_file("../dir2/baz", "dir1/foo3");
 
     #[cfg(unix)]
     ucmd.arg("dir1/foo1")
@@ -228,7 +228,7 @@ fn test_realpath_when_symlink_is_absolute_and_enoent() {
         .run()
         .stdout_contains("/dir2/bar\n")
         .stdout_contains("/dir2/baz\n")
-        .stderr_is("realpath: dir1/foo2: No such file or directory");
+        .stderr_is("realpath: dir1/foo2: No such file or directory\n");
 
     #[cfg(windows)]
     ucmd.arg("dir1/foo1")
@@ -239,3 +239,25 @@ fn test_realpath_when_symlink_is_absolute_and_enoent() {
         .stdout_contains("\\dir2\\baz\n")
         .stderr_is("realpath: dir1/foo2: No such file or directory");
 }
+
+#[test]
+#[ignore = "issue #3669"]
+fn test_realpath_when_symlink_part_is_missing() {
+    let (at, mut ucmd) = at_and_ucmd!();
+
+    at.mkdir("dir2");
+    at.touch("dir2/bar");
+
+    at.mkdir("dir1");
+    at.relative_symlink_file("../dir2/bar", "dir1/foo1");
+    at.relative_symlink_file("dir2/bar", "dir1/foo2");
+    at.relative_symlink_file("../dir2/baz", "dir1/foo3");
+    at.symlink_file("dir3/bar", "dir1/foo4");
+
+    ucmd.args(&["dir1/foo1", "dir1/foo2", "dir1/foo3", "dir1/foo4"])
+        .run()
+        .stdout_contains(at.plus_as_string("dir2/bar") + "\n")
+        .stdout_contains(at.plus_as_string("dir2/baz") + "\n")
+        .stderr_contains("realpath: dir1/foo2: No such file or directory\n")
+        .stderr_contains("realpath: dir1/foo4: No such file or directory\n");
+}
diff --git a/tests/common/util.rs b/tests/common/util.rs
index 97d435875..cae465d2b 100644
--- a/tests/common/util.rs
+++ b/tests/common/util.rs
@@ -702,8 +702,11 @@ impl AtPath {
     }
 
     pub fn relative_symlink_file(&self, original: &str, link: &str) {
-        log_info("symlink", &format!("{},{}", original, link));
-        symlink_file(original, link).unwrap();
+        log_info(
+            "symlink",
+            &format!("{},{}", original, &self.plus_as_string(link)),
+        );
+        symlink_file(original, &self.plus(link)).unwrap();
     }
 
     pub fn symlink_dir(&self, original: &str, link: &str) {
@@ -718,6 +721,14 @@ impl AtPath {
         symlink_dir(&self.plus(original), &self.plus(link)).unwrap();
     }
 
+    pub fn relative_symlink_dir(&self, original: &str, link: &str) {
+        log_info(
+            "symlink",
+            &format!("{},{}", original, &self.plus_as_string(link)),
+        );
+        symlink_dir(original, &self.plus(link)).unwrap();
+    }
+
     pub fn is_symlink(&self, path: &str) -> bool {
         log_info("is_symlink", self.plus_as_string(path));
         match fs::symlink_metadata(&self.plus(path)) {
diff --git a/tests/fixtures/comm/ab_delimiter_nul.expected b/tests/fixtures/comm/ab_delimiter_nul.expected
new file mode 100644
index 000000000..e56ec5cd7
Binary files /dev/null and b/tests/fixtures/comm/ab_delimiter_nul.expected differ