diff --git a/bin/dune b/bin/dune
index 9b0e082..186c456 100644
--- a/bin/dune
+++ b/bin/dune
@@ -1,5 +1,14 @@
 (executable
-  (name flake_env)
-  (public_name flake_env)
-  (libraries core core_unix core_unix.filename_unix core_unix.sys_unix ppx_yojson_conv re sha lib)
-  (preprocess (pps ppx_yojson_conv ppx_jane)))
\ No newline at end of file
+ (name flake_env)
+ (public_name flake_env)
+ (libraries
+  core
+  core_unix
+  core_unix.filename_unix
+  core_unix.sys_unix
+  ppx_yojson_conv
+  re
+  sha
+  lib)
+ (preprocess
+  (pps ppx_yojson_conv ppx_jane)))
diff --git a/bin/flake_env.re b/bin/flake_env.re
index 2615e9c..4567cb9 100644
--- a/bin/flake_env.re
+++ b/bin/flake_env.re
@@ -6,50 +6,52 @@ open Lib;
 let main = () => {
   let argv = Sys.get_argv();
   switch (Util.get_args(argv)) {
-  | Ok((layout_directory, flake_specifier, other_args)) => {
-      switch (preflight(layout_directory)) {
-      | Ok() => {
-          switch (Lib.Watches.get()) {
-          | Ok(watches) => {
-              let paths = Array.map(~f=watch => watch.path, watches);
-              let hash = Util.hash_files(paths);
-              let profile = layout_directory ++ "/flake-profile-" ++ hash;
-              let profile_rc = profile ++ ".rc";
+  | Ok((layout_directory, flake_specifier, other_args)) =>
+    switch (preflight(layout_directory)) {
+    | Ok () =>
+      switch (Lib.Watches.get()) {
+      | Ok(watches) =>
+        let paths = Array.map(~f=watch => watch.path, watches);
+        let hash = Util.hash_files(paths);
+        let profile = layout_directory ++ "/flake-profile-" ++ hash;
+        let profile_rc = profile ++ ".rc";
 
-              switch ((Sys_unix.is_file(profile_rc), Sys_unix.is_file(profile))) {
-              | (`Yes, `Yes) => {
-                  let profile_rc_mtime = Unix.stat(profile_rc).st_mtime;
-                  let all_older = Array.map(
-                    ~f=watch => watch.modtime, watches)
-                  |> Array.for_all(
-                      ~f=watch_mtime => watch_mtime <= int_of_float(profile_rc_mtime)
-                    )
-                  if (all_older) {
-                    print_cur_cache(profile_rc)
-                  } else {
-                    freshen_cache(layout_directory, hash, flake_specifier, other_args)
-                  }
-                }
-              | _ => freshen_cache(layout_directory, hash, flake_specifier, other_args)
-              }
-            };
-          | Error(e) => {
-              Printf.eprintf("%s\n", e);
-              exit(1);
-            }
-          }
-        }
-      | Error(e) => {
-          Printf.eprintf("%s\n", e);
-          exit(1);
-        }
-      };
-    }
-  | Error() => {
-      Printf.eprintf("%s  <layout_directory> <flake specifier> <...args>\n", argv[0]);
+        switch (Sys_unix.is_file(profile_rc), Sys_unix.is_file(profile)) {
+        | (`Yes, `Yes) =>
+          let profile_rc_mtime = Unix.stat(profile_rc).st_mtime;
+          let all_older =
+            Array.map(~f=watch => watch.modtime, watches)
+            |> Array.for_all(~f=watch_mtime =>
+                 watch_mtime <= int_of_float(profile_rc_mtime)
+               );
+          if (all_older) {
+            print_cur_cache(profile_rc);
+          } else {
+            freshen_cache(
+              layout_directory,
+              hash,
+              flake_specifier,
+              other_args,
+            );
+          };
+        | _ =>
+          freshen_cache(layout_directory, hash, flake_specifier, other_args)
+        };
+      | Error(e) =>
+        Printf.eprintf("%s\n", e);
+        exit(1);
+      }
+    | Error(e) =>
+      Printf.eprintf("%s\n", e);
       exit(1);
     }
-  }
+  | Error () =>
+    Printf.eprintf(
+      "%s  <layout_directory> <flake specifier> <...args>\n",
+      argv[0],
+    );
+    exit(1);
+  };
 };
 
 let () = main();
diff --git a/lib/dune b/lib/dune
index e268194..168d405 100644
--- a/lib/dune
+++ b/lib/dune
@@ -1,13 +1,15 @@
 (library
-  (name lib)
-  (public_name flake_env.lib)
-  (libraries
-    core
-    core_unix
-    core_unix.filename_unix
-    core_unix.sys_unix
-    ppx_yojson_conv
-    re
-    sha)
-  (instrumentation (backend bisect_ppx))
-  (preprocess (pps ppx_yojson_conv ppx_jane )))
\ No newline at end of file
+ (name lib)
+ (public_name flake_env.lib)
+ (libraries
+  core
+  core_unix
+  core_unix.filename_unix
+  core_unix.sys_unix
+  ppx_yojson_conv
+  re
+  sha)
+ (instrumentation
+  (backend bisect_ppx))
+ (preprocess
+  (pps ppx_yojson_conv ppx_jane)))
diff --git a/lib/flake_env__util.re b/lib/flake_env__util.re
index 0e8dfc5..1b5aa7b 100644
--- a/lib/flake_env__util.re
+++ b/lib/flake_env__util.re
@@ -39,12 +39,16 @@ let hash_files = filenames => {
 let rec rmrf = path => {
   switch (Unix.lstat(path).st_kind) {
   | exception (Unix.Unix_error(_, _, _)) => ()
-  | S_REG | S_LNK => Unix.unlink(path)
+  | S_REG
+  | S_LNK => Unix.unlink(path)
   | S_DIR =>
     Sys_unix.readdir(path)
     |> Array.iter(~f=name => rmrf(Filename.concat(path, name)));
     Unix.rmdir(path);
-  | _ => Printf.eprintf("Unsupported file type (Chr or Block device, FIFO, or Socket)\n")
+  | _ =>
+    Printf.eprintf(
+      "Unsupported file type (Chr or Block device, FIFO, or Socket)\n",
+    )
   };
 };
 
diff --git a/lib/flake_env__versions.re b/lib/flake_env__versions.re
index 1fbcd71..c36fb04 100644
--- a/lib/flake_env__versions.re
+++ b/lib/flake_env__versions.re
@@ -3,16 +3,13 @@ module Unix = Core_unix;
 
 module Util = Flake_env__util;
 
-
 type t = {
   major: int,
   minor: int,
   point: int,
 };
 
-let init = (major, minor, point) => {
-  {major, minor, point}
-};
+let init = (major, minor, point) => {major, minor, point};
 
 let required_direnv_version = init(2, 21, 3);
 
@@ -23,12 +20,12 @@ let semver_re = Re.compile(Re.Posix.re({|([0-9]+)\.([0-9]+)\.([0-9]+)|}));
 let compare = (a, b) => {
   switch (a, b) {
   | (a, b) when a.major == b.major && a.minor == b.minor && a.point == b.point => 0
-  | (a, b) when a.major < b.major => -1
-  | (a, b) when a.major == b.major && a.minor < b.minor => -1
-  | (a, b) when a.major == b.major && a.minor == b.minor && a.point < b.point => -1
+  | (a, b) when a.major < b.major => (-1)
+  | (a, b) when a.major == b.major && a.minor < b.minor => (-1)
+  | (a, b) when a.major == b.major && a.minor == b.minor && a.point < b.point => (-1)
   | _ => 1
-  }
-}
+  };
+};
 
 let extract_version_number = cmd => {
   switch (Util.run_process(cmd, ["--version"])) {
@@ -55,31 +52,33 @@ let extract_version_number = cmd => {
 
 let is_new_enough = (cur, needed) => {
   switch (cur) {
-    | Ok(cur) => {
-        switch (compare(cur, needed)) {
-        | x when x < 0 => Ok(false)
-        | _ => Ok(true)
-        }
-      }
-    | Error(e) => Error(e)
-  }
+  | Ok(cur) =>
+    switch (compare(cur, needed)) {
+    | x when x < 0 => Ok(false)
+    | _ => Ok(true)
+    }
+  | Error(e) => Error(e)
+  };
 };
 
-let in_direnv = () => switch (Sys.getenv("direnv")) {
-    | Some(_) => true
-    | None => false
-};
+let in_direnv = () =>
+  switch (Sys.getenv("direnv")) {
+  | Some(_) => true
+  | None => false
+  };
 
 let preflight_versions = () => {
-  let is_nix_new_enough = is_new_enough(extract_version_number("nix"), required_nix_version);
-  let is_direnv_new_enough = is_new_enough(extract_version_number("direnv"), required_direnv_version);
+  let is_nix_new_enough =
+    is_new_enough(extract_version_number("nix"), required_nix_version);
+  let is_direnv_new_enough =
+    is_new_enough(extract_version_number("direnv"), required_direnv_version);
 
   switch (in_direnv(), is_direnv_new_enough, is_nix_new_enough) {
-    | (false, _, _) => Error("Not in direnv!")
-    | (_, Ok(false), _) => Error("Direnv version is not new enough")
-    | (_, _, Ok(false)) => Error("Nix version is not new enough")
-    | (_, Error(e), _) => Error(e)
-    | (_, _, Error(e)) => Error(e)
-    | (true, Ok(true), Ok(true)) => Ok()
-  }
+  | (false, _, _) => Error("Not in direnv!")
+  | (_, Ok(false), _) => Error("Direnv version is not new enough")
+  | (_, _, Ok(false)) => Error("Nix version is not new enough")
+  | (_, Error(e), _) => Error(e)
+  | (_, _, Error(e)) => Error(e)
+  | (true, Ok(true), Ok(true)) => Ok()
+  };
 };
diff --git a/lib/flake_env__watches.re b/lib/flake_env__watches.re
index db4cfc7..5f0ee3e 100644
--- a/lib/flake_env__watches.re
+++ b/lib/flake_env__watches.re
@@ -9,40 +9,52 @@ module Util = Flake_env__util;
 type watch = {
   exists: bool,
   modtime: int,
-  path: string
+  path: string,
 };
 
 [@deriving yojson]
-type watches = array<watch>;
+type watches = array(watch);
 
 let get = () => {
-  let direnv_watch_str = Sys.getenv("DIRENV_WATCHES") |> Option.value_exn(~message="Environment missing DIRENV_WATCHES");
-  let proc_info = Unix.create_process(~prog="direnv", ~args=["show_dump", direnv_watch_str]);
+  let direnv_watch_str =
+    Sys.getenv("DIRENV_WATCHES")
+    |> Option.value_exn(~message="Environment missing DIRENV_WATCHES");
+  let proc_info =
+    Unix.create_process(
+      ~prog="direnv",
+      ~args=["show_dump", direnv_watch_str],
+    );
   let sub_stdout = Unix.in_channel_of_descr(proc_info.stdout);
 
   switch (Unix.waitpid(proc_info.pid)) {
-    | Ok() => Ok(watches_of_yojson(Yojson.Safe.from_channel(sub_stdout)))
-    | _ => Error("Failed to parse watches")
-  }
+  | Ok () => Ok(watches_of_yojson(Yojson.Safe.from_channel(sub_stdout)))
+  | _ => Error("Failed to parse watches")
+  };
 };
 
-let get_path = (doc) => String.drop_prefix(doc |> member("path") |> to_string, 11);
+let get_path = doc =>
+  String.drop_prefix(doc |> member("path") |> to_string, 11);
 
 let rec get_paths_from_doc = (doc, paths) => {
   let p = get_path(doc);
-  let sub_paths = List.concat(
-    doc |> member("inputs")
-        |> to_assoc
-        |> List.map(~f=((_k, v)) => get_paths_from_doc(v, paths)));
-  List.concat([[p], sub_paths])
+  let sub_paths =
+    List.concat(
+      doc
+      |> member("inputs")
+      |> to_assoc
+      |> List.map(~f=((_k, v)) => get_paths_from_doc(v, paths)),
+    );
+  List.concat([[p], sub_paths]);
 };
 
 let get_input_paths = () => {
   switch (Util.nix(["flake", "archive", "--json", "--no-write-lock-file"])) {
-  | (Ok(), output) => get_paths_from_doc(Yojson.Safe.from_string(output), [])
-  | (Error(_), _) => {
-      Printf.eprintf("Failed to parse output of `nix flake archive --json`. Ignorning flake inputs. \n");
-      []
-    }
-  }
+  | (Ok (), output) =>
+    get_paths_from_doc(Yojson.Safe.from_string(output), [])
+  | (Error(_), _) =>
+    Printf.eprintf(
+      "Failed to parse output of `nix flake archive --json`. Ignorning flake inputs. \n",
+    );
+    [];
+  };
 };
diff --git a/lib/lib.re b/lib/lib.re
index a9a1f6e..e411503 100644
--- a/lib/lib.re
+++ b/lib/lib.re
@@ -5,11 +5,11 @@ module Util = Flake_env__util;
 module Watches = Flake_env__watches;
 module Versions = Flake_env__versions;
 
-let print_cur_cache = (profile_rc) => {
-  In_channel.read_all(profile_rc) |> Printf.printf("%s")
+let print_cur_cache = profile_rc => {
+  In_channel.read_all(profile_rc) |> Printf.printf("%s");
 };
 
-let clean_old_gcroots = (layout_dir) => {
+let clean_old_gcroots = layout_dir => {
   Util.rmrf(layout_dir ++ "/flake-inputs/");
   Util.rmrf(layout_dir);
   Unix.mkdir_p(layout_dir ++ "/flake-inputs/");
@@ -17,57 +17,80 @@ let clean_old_gcroots = (layout_dir) => {
 
 let add_gcroot = (store_path, symlink) => {
   switch (Util.nix(["build", "--out-link", symlink, store_path])) {
-  | (Ok(), _) => Ok()
+  | (Ok (), _) => Ok()
   | (err, _) => err
-  }
+  };
 };
 
 let freshen_cache = (layout_dir, hash, flake_specifier, other_args) => {
-    clean_old_gcroots(layout_dir);
-    let tmp_profile = layout_dir ++ "flake-tmp-profile."  ++ Core.Pid.to_string(Core_unix.getpid());
+  clean_old_gcroots(layout_dir);
+  let tmp_profile =
+    layout_dir
+    ++ "flake-tmp-profile."
+    ++ Core.Pid.to_string(Core_unix.getpid());
 
-    let pde_args = ["print-dev-env", "--profile", tmp_profile, flake_specifier, ...other_args];
-    let (exit_code, stdout_content) = Util.nix(pde_args);
+  let pde_args = [
+    "print-dev-env",
+    "--profile",
+    tmp_profile,
+    flake_specifier,
+    ...other_args,
+  ];
+  let (exit_code, stdout_content) = Util.nix(pde_args);
 
-    let profile = layout_dir ++ "/flake-profile-" ++ hash;
-    let profile_rc = profile ++ ".rc";
+  let profile = layout_dir ++ "/flake-profile-" ++ hash;
+  let profile_rc = profile ++ ".rc";
 
-    switch (exit_code) {
-    | Ok() => {
-        Out_channel.with_file(~f=f=> Out_channel.output_string(f, stdout_content), profile_rc);
-        switch (add_gcroot(tmp_profile, profile)) {
-        | Ok() => {
-            Sys_unix.remove(tmp_profile);
-            let flake_input_cache_path = layout_dir ++ "/flake-inputs/"
-              let flake_inputs = Watches.get_input_paths();
-            flake_inputs |> List.iter(~f=(inpt) => {
-                switch (add_gcroot("/nix/store/" ++ inpt, flake_input_cache_path ++ inpt)) {
-                | Ok() => ()
-                | err => Printf.eprintf("Failed creating flake-input gcroot: %s\n", Core_unix.Exit_or_signal.to_string_hum(err));
-                };
-              });
-            print_cur_cache(profile_rc);
-          }
-        | err => {
-            Printf.eprintf("Failed creating gcroot: %s\n", Core_unix.Exit_or_signal.to_string_hum(err));
-            exit(1);
-          }
-        };
-      }
-    | err => {
-        Printf.eprintf("Failed evaluating flake: %s\n", Core_unix.Exit_or_signal.to_string_hum(err));
-        exit(1);
-      }
+  switch (exit_code) {
+  | Ok () =>
+    Out_channel.with_file(
+      ~f=f => Out_channel.output_string(f, stdout_content),
+      profile_rc,
+    );
+    switch (add_gcroot(tmp_profile, profile)) {
+    | Ok () =>
+      Sys_unix.remove(tmp_profile);
+      let flake_input_cache_path = layout_dir ++ "/flake-inputs/";
+      let flake_inputs = Watches.get_input_paths();
+      flake_inputs
+      |> List.iter(~f=inpt => {
+           switch (
+             add_gcroot("/nix/store/" ++ inpt, flake_input_cache_path ++ inpt)
+           ) {
+           | Ok () => ()
+           | err =>
+             Printf.eprintf(
+               "Failed creating flake-input gcroot: %s\n",
+               Core_unix.Exit_or_signal.to_string_hum(err),
+             )
+           }
+         });
+      print_cur_cache(profile_rc);
+    | err =>
+      Printf.eprintf(
+        "Failed creating gcroot: %s\n",
+        Core_unix.Exit_or_signal.to_string_hum(err),
+      );
+      exit(1);
     };
+  | err =>
+    Printf.eprintf(
+      "Failed evaluating flake: %s\n",
+      Core_unix.Exit_or_signal.to_string_hum(err),
+    );
+    exit(1);
   };
+};
 
-let preflight = (layout_directory) => {
-  switch (Versions.preflight_versions(), Sys_unix.is_directory(layout_directory)) {
+let preflight = layout_directory => {
+  switch (
+    Versions.preflight_versions(),
+    Sys_unix.is_directory(layout_directory),
+  ) {
   | (Ok(_), `Yes) => Ok()
-  | (Ok(_), _) => {
-      Unix.mkdir_p(layout_directory);
-      Ok()
-    }
+  | (Ok(_), _) =>
+    Unix.mkdir_p(layout_directory);
+    Ok();
   | (err, _) => err
-  }
-}
+  };
+};
diff --git a/tests/dune b/tests/dune
index deb6af3..dce3e4c 100644
--- a/tests/dune
+++ b/tests/dune
@@ -1,13 +1,10 @@
 (tests
-  (names
-    flake_env_test_versions
-    flake_env_test_watches
-    flake_env_test_util)
-  (deps spit_version.sh spit_gibberish.sh)
-  (libraries
-    lib
-    alcotest
-    core
-    core_unix
-    core_unix.sys_unix
-    core_unix.filename_unix))
\ No newline at end of file
+ (names flake_env_test_versions flake_env_test_watches flake_env_test_util)
+ (deps spit_version.sh spit_gibberish.sh)
+ (libraries
+  lib
+  alcotest
+  core
+  core_unix
+  core_unix.sys_unix
+  core_unix.filename_unix))
diff --git a/tests/flake_env_test_util.re b/tests/flake_env_test_util.re
index 6f8e11f..e45ccaf 100644
--- a/tests/flake_env_test_util.re
+++ b/tests/flake_env_test_util.re
@@ -111,7 +111,11 @@ let test_get_args_just_enough = () => {
 };
 
 let test_get_args_error = () => {
-  check_get_args("Errors on too few args", Error(), get_args([|"000", "111"|]))
+  check_get_args(
+    "Errors on too few args",
+    Error(),
+    get_args([|"000", "111"|]),
+  );
 };
 
 let () =
@@ -148,11 +152,15 @@ let () =
         ),
         (
           "get_args",
-        [
-          test_case("Parses Args", `Quick, test_get_args_simple),
-          test_case("Parses just enough args", `Quick, test_get_args_just_enough),
-          test_case("Handles too few args", `Quick, test_get_args_error)
-        ],
+          [
+            test_case("Parses Args", `Quick, test_get_args_simple),
+            test_case(
+              "Parses just enough args",
+              `Quick,
+              test_get_args_just_enough,
+            ),
+            test_case("Handles too few args", `Quick, test_get_args_error),
+          ],
         ),
       ],
     )
diff --git a/tests/flake_env_test_versions.re b/tests/flake_env_test_versions.re
index ac5214a..b0f7208 100644
--- a/tests/flake_env_test_versions.re
+++ b/tests/flake_env_test_versions.re
@@ -105,15 +105,24 @@ let test_extract_version_number_success = () => {
 
 let test_extract_version_number_no_version = () => {
   let result = Versions.extract_version_number("../tests/spit_gibberish.sh");
-  check_version("Versions", Error("Stdout did not contain a version number for `../tests/spit_gibberish.sh --version`"), result);
+  check_version(
+    "Versions",
+    Error(
+      "Stdout did not contain a version number for `../tests/spit_gibberish.sh --version`",
+    ),
+    result,
+  );
 };
 
 let test_extract_version_number_nonexistent = () => {
   let result = Versions.extract_version_number("nonexistent.sh");
-  check_version("Versions", Error("Failed executing 'nonexistent.sh'"), result);
+  check_version(
+    "Versions",
+    Error("Failed executing 'nonexistent.sh'"),
+    result,
+  );
 };
 
-
 // TODO: Test:
 // * preflight_versions? impure, but m
 let () =
@@ -177,8 +186,16 @@ let () =
           "extract_version_number",
           [
             test_case("success", `Quick, test_extract_version_number_success),
-            test_case("no version number", `Quick, test_extract_version_number_no_version),
-            test_case("missing binary", `Quick, test_extract_version_number_nonexistent),
+            test_case(
+              "no version number",
+              `Quick,
+              test_extract_version_number_no_version,
+            ),
+            test_case(
+              "missing binary",
+              `Quick,
+              test_extract_version_number_nonexistent,
+            ),
           ],
         ),
       ],
diff --git a/tests/flake_env_test_watches.re b/tests/flake_env_test_watches.re
index 38d4226..0a60efb 100644
--- a/tests/flake_env_test_watches.re
+++ b/tests/flake_env_test_watches.re
@@ -1,41 +1,60 @@
 open Lib.Watches;
 
 let test_get_path_removes_prefix = () => {
-  let input = `Assoc([
-    ("path", `String("aaaaaaaaaaabbbbb"))
-  ]);
-  Alcotest.(check(string))("Prefix removed", "bbbbb", get_path(input))
+  let input = `Assoc([("path", `String("aaaaaaaaaaabbbbb"))]);
+  Alcotest.(check(string))("Prefix removed", "bbbbb", get_path(input));
 };
 
 let test_get_paths_from_doc = () => {
-  let input = `Assoc([
-    ("path", `String("aaaaaaaaaaabbbbb")),
-    ("inputs", `Assoc([
-    ("foo", `Assoc([
-      ("path", `String("aaaaaaaaaaaccccc")),
-      ("inputs", `Assoc([
-      ("bar", `Assoc([
-        ("path", `String("aaaaaaaaaaaddddd")),
-        ("inputs", `Assoc([]))
-      ]))
-    ]))
-    ]))
-  ]))
-  ]);
-  Alcotest.(check(list(string)))("Gathers all inputs", ["bbbbb", "ccccc", "ddddd"], get_paths_from_doc(input, []))
+  let input =
+    `Assoc([
+      ("path", `String("aaaaaaaaaaabbbbb")),
+      (
+        "inputs",
+        `Assoc([
+          (
+            "foo",
+            `Assoc([
+              ("path", `String("aaaaaaaaaaaccccc")),
+              (
+                "inputs",
+                `Assoc([
+                  (
+                    "bar",
+                    `Assoc([
+                      ("path", `String("aaaaaaaaaaaddddd")),
+                      ("inputs", `Assoc([])),
+                    ]),
+                  ),
+                ]),
+              ),
+            ]),
+          ),
+        ]),
+      ),
+    ]);
+  Alcotest.(check(list(string)))(
+    "Gathers all inputs",
+    ["bbbbb", "ccccc", "ddddd"],
+    get_paths_from_doc(input, []),
+  );
 };
 
 let () =
   Alcotest.(
-  run(
-    "Watches",
-    [("get_path",
+    run(
+      "Watches",
       [
-      test_case("Removes prefix", `Quick, test_get_path_removes_prefix),
-    ]),
-     ("get_paths_from_doc",
-      [
-       test_case("Collects all paths", `Quick, test_get_paths_from_doc),
-     ])
-  ]),
-);
+        (
+          "get_path",
+          [
+            test_case("Removes prefix", `Quick, test_get_path_removes_prefix),
+          ],
+        ),
+        (
+          "get_paths_from_doc",
+          [test_case("Collects all paths", `Quick, test_get_paths_from_doc)],
+        ),
+      ],
+    )
+  );