diff --git a/build.py b/build.py
index d2a4572..3cbd166 100644
--- a/build.py
+++ b/build.py
@@ -11,18 +11,19 @@ ARGS = "-fdiagnostics-color -pthread -Wall -std=c17 -pedantic -g"
 
 SOURCE_DIR = Path("source/")
 OBJECT_DIR = Path("objects/")
-OUTPUT = Path("debug")
+OUTPUT = Path("build/debug")
 
 
-CHECKSUMS = Path("checksums.txt")
-ERRORS = Path("errors.txt")
+SRC_CHECKSUMS_TXT = Path("build/src_checksums.txt")
+HDR_CHECKSUMS_TXT = Path("build/hdr_checksums.txt")
+ERRORS_TXT = Path("build/errors.txt")
 
 
-def scan_checksums(files: list[Path]) -> list[str]:
-    return (md5(file.read_bytes()).hexdigest() for file in files)
+def scan_checksums(files) -> list[str]:
+    return [md5(file.read_bytes()).hexdigest() for file in files]
 
 
-def read_txt(txt: Path) -> any:
+def read_text(txt: Path) -> any:
     if not txt.exists():
         return []
     
@@ -30,84 +31,108 @@ def read_txt(txt: Path) -> any:
     return json.loads(content) if content else []
 
 
-def write_txt(txt: Path, content) -> None:
+def write_text(txt: Path, content) -> None:
     txt.write_text(json.dumps(content))
 
 
-def difference(cur, old, vals):
-    return (vals[cur.index(i)] for i in set(cur) - set(old))
+def checksum_difs(cur, old, files) -> set[str]:
+    dif = set(cur) - set(old)
+    return ({files[cur.index(i)] for i in dif}, dif)
 
 
-def clean_objects(object_dir: Path, sources: list[Path]) -> None:
-    objects: list[Path] = [object for object in object_dir.rglob("*.o")]
+def delete_unused_objects(object_dir: Path, source_stems: list[str]) -> None:
+    objects = [object for object in object_dir.rglob("*.o")]
 
-    object_stems = [object.stem for object in objects]
-    source_stems = [source.stem for source in sources]
-
-    for stem in set(object_stems).difference(source_stems):
-        objects[object_stems.index(stem)].unlink()
+    map(Path.unlink, [object for object in objects if object.stem not in source_stems])
 
 
-def header_dependencies(sources):
-    tasks = []
+def paths_to_args(args: list[Path], sep: str="") -> str:
+    return " ".join(f"{sep}{arg}" for arg in args)
+
+
+def dispatch(args):
+    return subprocess.Popen(args, stdout=PIPE, stderr=PIPE, text=True, encoding="utf-8")
+
+
+def header_deps(sources, includes):
+    incl = paths_to_args(includes, "-I ")
+    src = paths_to_args(sources)
+    out, err = dispatch(f"{GCC} -MM {src} {ARGS} {incl}").communicate()
+
+    dependencies = []
+    if out:
+        for line in out.splitlines():
+            if ":" in line:
+                dependencies.append(set())
+
+            dependencies[-1].add(Path(line.strip(" \\")))
+
+    return dependencies
+
+
+def compile_job(sources, includes, errors, object_dir):
+    incl = paths_to_args(includes, "-I ")
+
+    processes = []
     for source in sources:
-        task = subprocess.Popen(f"{GCC} -MMD {source} {ARGS} -o stdout", stdout=PIPE)
-        tasks.append(task)
+        output = object_dir.joinpath(source.with_suffix(".o").name)
 
-    for task in tasks:
-        
+        processes.append(dispatch(f"{GCC} -c {source} {ARGS} {incl} -o {output}"))
+
+    for process, source in zip(processes, sources):
+        out, err = process.communicate()
+        errors[source.stem] = err
 
 
-def compile(source: Path, includes: list[Path], object_dir: Path):
-    include_arg: str = " ".join(f"-I {dir}" for dir in includes)
-    output: Path = object_dir / source.with_suffix(".o").name
-
-    args = f"{GCC} -c {source} {ARGS} {include_arg} -o {output}"
-
-    return subprocess.Popen(args, stderr=subprocess.PIPE)
-
-
-def wait_compile_tasks(tasks, updated_sources) -> dict[str, str]:
-    errors = disk_read_errors(ERRORS)
-
-    for task, source in zip(tasks, updated_sources):
-        out, err = task.communicate()
-        if err:
-            errors[str(source)] = err.decode("utf-8")
-        else:
-            errors[str(source)] = False
-
-    disk_write_errors(ERRORS, errors)
-    return errors
-
-
-def link(object_dir: Path, output: Path) -> None:
-    subprocess.run(f"{GCC} {object_dir}/*.o {ARGS} -o {output}")
+def link_job(object_dir, output):
+    out, err = dispatch(f"{GCC} {object_dir}/*.o {ARGS} -o {output}").communicate()
+    return err
 
 
 def build(src: Path, object_dir: Path, output: Path):
-    includes, headers, sources = zip(map(src.rglob, ["*/", "*.h", "*.c"]))
+    # Walk source directory, obtain checksums
+    includes, headers, sources = map(list, map(src.rglob, ["*/", "*.h", "*.c"]))
 
-    headers_cur, sources_cur = map(scan_checksums, (headers, sources))
-    headers_old, sources_old = read_txt(CHECKSUMS)
+    hc_cur, sc_cur = scan_checksums(headers), scan_checksums(sources)
+    hc_old, sc_old = read_text(HDR_CHECKSUMS_TXT), read_text(SRC_CHECKSUMS_TXT)
 
-    headers_updt = difference(headers_cur, headers_old, headers)
-    sources_updt = difference(sources_cur, sources_old, sources)
+    # Find out which sources need to be compiled based on checksum differences
+    # and dependencies on changed headers
+    header_updates, hc_updates = checksum_difs(hc_cur, hc_old, headers)
+    source_updates, sc_updates = checksum_difs(sc_cur, sc_old, sources)
 
-    dependencies = {}
+    for source_dependencies, source in zip(header_deps(sources, includes), sources):
+        if any(header in header_updates for header in source_dependencies):
+            source_updates.add(source)
 
-    tasks = []
-    for source in updated_sources:
-        tasks.append(compile(source, includes, object_dir))
+    # Compile step: Read old error messages, then update, print, and write them
+    errors = dict(read_text(ERRORS_TXT))
+    compile_job(source_updates, includes, errors, object_dir)
 
-    errors = wait_compile_tasks(tasks, updated_sources).values()
+    error_amt = 0
+    source_stems = [source.stem for source in sources]
+    for source_stem, message in list(errors.items()):
+        if source_stem not in source_stems:
+            errors.pop(source_stem)
+        elif message:
+            print(message)
+            error_amt += 1
+        else:
+            sc_updates.remove(sc_cur[source_stems.index(source_stem)])
 
-    print("\n".join(err for err in errors if err is not False).strip("\n"))
+    write_text(HDR_CHECKSUMS_TXT, list(hc_updates))
+    write_text(SRC_CHECKSUMS_TXT, list(sc_updates))
+    write_text(ERRORS_TXT, errors)
 
+    # Link step: Delete unused objects, link and print the error message
+    delete_unused_objects(object_dir, [source.stem for source in sources])
+    link_err = link_job(object_dir, output)
 
-    clean_objects(object_dir, all_sources)
-    link(object_dir, output)
-    print(f"Compiled: {len(updated_sources)} Linked: {len(all_sources)}")
+    if link_err:
+        print(link_err)
+
+    # yippee
+    print(f"Compiled: {len(source_updates)} Linked: {len(sources)} Errored: {error_amt}")
 
 
 if __name__ == "__main__":
diff --git a/build/debug.exe b/build/debug.exe
new file mode 100644
index 0000000..eda6b15
Binary files /dev/null and b/build/debug.exe differ
diff --git a/build/errors.txt b/build/errors.txt
new file mode 100644
index 0000000..9dde9e6
--- /dev/null
+++ b/build/errors.txt
@@ -0,0 +1 @@
+{"tetr": "", "ringbuffer": "", "event": "", "ctrl": "", "terminal": "", "fumoengine": "", "parseinput": "", "dictionary": "", "fumocommon": "", "win": "", "input": "", "fumotris": "", "vector": ""}
\ No newline at end of file
diff --git a/build/hdr_checksums.txt b/build/hdr_checksums.txt
new file mode 100644
index 0000000..ed1b7c8
--- /dev/null
+++ b/build/hdr_checksums.txt
@@ -0,0 +1 @@
+["0d7597ffd48812c52d3f02731cbf693f", "6669fc7fcffc77563f1315cb7710ec82", "fbccab3d5cd1838cbf8ad1d4e2a7c03b", "1d6bdf7e8de4ac751252b67027e5d57e", "330b6f9493d091e7c340c1434b6f80b4", "a3dca3fbce775b791384bec8abc3f0c3", "f61af2abe56cd6881a830ae6222483e9", "1cdcae043579aa6406b9823b5f52aedd", "088145536b04ef82517eb93630888dff", "1420f33d62a8ed8429c8f1a96f1ab33e", "e38bd5ea2b554a21849158242a2add8e", "9df90eabc8908cac60aa774d335a106c", "333c7211bb2c72ad321495f53d11bff0", "dc6df72158812bc9f6ed484a4cfb046b"]
\ No newline at end of file
diff --git a/build/src_checksums.txt b/build/src_checksums.txt
new file mode 100644
index 0000000..0637a08
--- /dev/null
+++ b/build/src_checksums.txt
@@ -0,0 +1 @@
+[]
\ No newline at end of file
diff --git a/checksums.txt b/checksums.txt
deleted file mode 100644
index 136d8cd..0000000
--- a/checksums.txt
+++ /dev/null
@@ -1 +0,0 @@
-{"source\\fumoengine\\fumocommon.c": "bdd12a9257829d191f57d442b068db37", "source\\fumoengine\\fumoengine.c": "f3097febe6401acf6d0d8b3032b2da68", "source\\fumotris\\fumotris.c": "1516eb830de511f7987507be279e6f02", "source\\fumotris\\tetr.c": "74901782ad0d235bb6b078d2bb6ef99e", "source\\fumoengine\\include\\dictionary.c": "c8f8e5f99965c5c82caf24790fed78e4", "source\\fumoengine\\include\\event.c": "140ba30120636d5d33875e43447e0642", "source\\fumoengine\\include\\ringbuffer.c": "0d552f9daeeebd7ef23f4aaa7ae3e022", "source\\fumoengine\\include\\vector.c": "3f2ccd6831013ac0428446c776891503", "source\\fumoengine\\input\\ctrl.c": "6113d9b6cbcef5daed308f96a0a96f18", "source\\fumoengine\\input\\input.c": "7004fde9604dd57325d623cf9775b33c", "source\\fumoengine\\terminal\\terminal.c": "42b3d4217c15403b6dd079cee4a68186", "source\\fumoengine\\input\\platforms\\parseinput.c": "e23dafd399743096db434a9869b3b47e", "source\\fumoengine\\input\\platforms\\win.c": "f52c9c1bab5d1f05d78f0420780d486a"}
\ No newline at end of file
diff --git a/debug.exe b/debug.exe
deleted file mode 100644
index 7710785..0000000
Binary files a/debug.exe and /dev/null differ
diff --git a/errors.txt b/errors.txt
deleted file mode 100644
index 8dc07da..0000000
--- a/errors.txt
+++ /dev/null
@@ -1 +0,0 @@
-{"source\\fumoengine\\terminal\\terminal.c": false, "source\\fumoengine\\fumocommon.c": false, "source\\fumoengine\\include\\event.c": false, "source\\fumoengine\\include\\ringbuffer.c": false, "source\\fumoengine\\input\\platforms\\win.c": false, "source\\fumotris\\tetr.c": "\u001b[01m\u001b[Ksource\\fumotris\\tetr.c:\u001b[m\u001b[K In function '\u001b[01m\u001b[KTetrMapDraw\u001b[m\u001b[K':\n\u001b[01m\u001b[Ksource\\fumotris\\tetr.c:43:31:\u001b[m\u001b[K \u001b[01;31m\u001b[Kerror: \u001b[m\u001b[Kunknown type name '\u001b[01m\u001b[Kff\u001b[m\u001b[K'\n   43 |             block[0].ch = '(';\u001b[01;31m\u001b[Kff\u001b[m\u001b[K\n      |                               \u001b[01;31m\u001b[K^~\u001b[m\u001b[K\n\u001b[01m\u001b[Ksource\\fumotris\\tetr.c:44:21:\u001b[m\u001b[K \u001b[01;31m\u001b[Kerror: \u001b[m\u001b[Kexpected '\u001b[01m\u001b[K=\u001b[m\u001b[K', '\u001b[01m\u001b[K,\u001b[m\u001b[K', '\u001b[01m\u001b[K;\u001b[m\u001b[K', '\u001b[01m\u001b[Kasm\u001b[m\u001b[K' or '\u001b[01m\u001b[K__attribute__\u001b[m\u001b[K' before '\u001b[01m\u001b[K.\u001b[m\u001b[K' token\n   44 |             block[1]\u001b[01;31m\u001b[K.\u001b[m\u001b[Kch = ')';\n      |                     \u001b[01;31m\u001b[K^\u001b[m\u001b[K\n", "source\\fumoengine\\include\\vector.c": false, "source\\fumoengine\\input\\platforms\\parseinput.c": false, "source\\fumoengine\\include\\dictionary.c": false, "source\\fumoengine\\input\\ctrl.c": false, "source\\fumoengine\\input\\input.c": false, "source\\fumotris\\fumotris.c": false, "source\\fumoengine\\fumoengine.c": false}
\ No newline at end of file
diff --git a/objects/ctrl.o b/objects/ctrl.o
index f2a1548..25339a9 100644
Binary files a/objects/ctrl.o and b/objects/ctrl.o differ
diff --git a/objects/dictionary.o b/objects/dictionary.o
index 73eff4b..763d6d4 100644
Binary files a/objects/dictionary.o and b/objects/dictionary.o differ
diff --git a/objects/event.o b/objects/event.o
index 62bdaea..95dd92c 100644
Binary files a/objects/event.o and b/objects/event.o differ
diff --git a/objects/fumocommon.o b/objects/fumocommon.o
index 11ad76f..ce43889 100644
Binary files a/objects/fumocommon.o and b/objects/fumocommon.o differ
diff --git a/objects/fumoengine.o b/objects/fumoengine.o
index 059f6f6..71fbb76 100644
Binary files a/objects/fumoengine.o and b/objects/fumoengine.o differ
diff --git a/objects/fumotris.o b/objects/fumotris.o
index be7b2bd..479d292 100644
Binary files a/objects/fumotris.o and b/objects/fumotris.o differ
diff --git a/objects/input.o b/objects/input.o
index 262c725..481c498 100644
Binary files a/objects/input.o and b/objects/input.o differ
diff --git a/objects/parseinput.o b/objects/parseinput.o
index 4c32f02..d82f6db 100644
Binary files a/objects/parseinput.o and b/objects/parseinput.o differ
diff --git a/objects/ringbuffer.o b/objects/ringbuffer.o
index 2b6f442..0c42d27 100644
Binary files a/objects/ringbuffer.o and b/objects/ringbuffer.o differ
diff --git a/objects/terminal.o b/objects/terminal.o
index 8d4b93e..15f1c79 100644
Binary files a/objects/terminal.o and b/objects/terminal.o differ
diff --git a/objects/tetr.o b/objects/tetr.o
index cf44bcc..4966281 100644
Binary files a/objects/tetr.o and b/objects/tetr.o differ
diff --git a/objects/vector.o b/objects/vector.o
index ce95fa7..573ad7c 100644
Binary files a/objects/vector.o and b/objects/vector.o differ
diff --git a/objects/win.o b/objects/win.o
index 29f940c..97ef881 100644
Binary files a/objects/win.o and b/objects/win.o differ
diff --git a/test.exe b/test.exe
deleted file mode 100644
index cd52a73..0000000
Binary files a/test.exe and /dev/null differ