fix error when building from dtx files

wait for subprocess to complete
    catch some more errors

build/build.py

@@ -148,7 +148,7 @@ def build(
             elif not str(file.relative_to(output_dir)) in built_files:
                 if not file.is_dir() and not str(file.relative_to(output_dir)) == 'build_info.json':
                     # PyTeX does not at all know something about this file
-                    raise UnknownFileInBuildDirectory(file.relative_to(output_dir))
+                    raise UnknownFileInBuildDirectoryError(file.relative_to(output_dir))
 
     if write_build_information:
         with open(output_dir / 'build_info.json', 'w') as f:

default_formatters/docstrip_formatter.py

@@ -4,6 +4,7 @@ import subprocess
 
 from PyTeX.formatter import Formatter
 from PyTeX.utils import ensure_file_integrity
+from PyTeX.errors import FileNotGeneratedFromDTXFileError, LatexMKError
 
 
 class DocstripFormatter(Formatter):
@@ -19,13 +20,20 @@ class DocstripFormatter(Formatter):
                     relative_name: Optional[str] = None,
                     last_build_info: Optional[List[Dict]] = None) -> List[str]:
         ensure_file_integrity(output_dir / self.filename, str(Path(relative_name).parent / self.filename), last_build_info)
-        result = subprocess.Popen(['pdflatex', self.name + '.dtx'], cwd=str(input_path.parent),
+        try:
+            result = subprocess.run(['latexmk', '-gg', '-output-directory=/tmp'], cwd=str(input_path.parent),
                                       stdout=subprocess.DEVNULL,
                                       stderr=subprocess.DEVNULL
                                       )
+        except subprocess.CalledProcessError:
+            raise LatexMKError(self.filename)
         if not result:
             pass
-        sty = input_path.with_suffix('.sty').read_text()
+        sty_file = (Path('/tmp') / input_path.with_suffix('.sty').name)
+        if sty_file.exists():
+            sty = sty_file.read_text()
+        else:
+            raise FileNotGeneratedFromDTXFileError(self.filename, 'style')
         output_dir.mkdir(parents=True, exist_ok=True)
         (output_dir / self.filename).write_text(sty)
         return [self.filename]

errors/__init__.py

@@ -1,6 +1,6 @@
 from .errors import PyTexError, SubmoduleDirtyForbiddenError, ProgrammingError, ExtraHeaderFileNotFoundError, \
     UnknownTexVersionError, ModifiedFileInBuildDirectoryError, UnknownFileInBuildDirectoryNoOverwriteError, \
-    UnknownFileInBuildDirectory
+    UnknownFileInBuildDirectoryError, LatexMKError, FileNotGeneratedFromDTXFileError
 
 __all__ = [
     'PyTexError',
@@ -10,5 +10,7 @@ __all__ = [
     'UnknownTexVersionError',
     'ModifiedFileInBuildDirectoryError',
     'UnknownFileInBuildDirectoryNoOverwriteError',
-    'UnknownFileInBuildDirectory'
+    'UnknownFileInBuildDirectoryError',
+    'LatexMKError',
+    'FileNotGeneratedFromDTXFileError'
 ]

errors/errors.py

@@ -56,10 +56,28 @@ class UnknownFileInBuildDirectoryNoOverwriteError(PyTexError):
         )
 
 
-class UnknownFileInBuildDirectory(PyTexError):
+class UnknownFileInBuildDirectoryError(PyTexError):
     def __init__(self, filename):
         super().__init__(
             f"Detected unknown file {filename} in build directory."
             f"PyTeX has no knowledge about this, you should probably"
             f"remove it."
         )
+
+
+class LatexMKError(PyTexError):
+    def __init__(self, filename):
+        super().__init__(
+            f"Running latexmk on file {filename} resulted in an error. "
+            f"Make sure this file is well-formed and an appropriate "
+            f"'.latexmkrc' is present in its directory."
+        )
+
+
+class FileNotGeneratedFromDTXFileError(PyTexError):
+    def __init__(self, filename, type):
+        super().__init__(
+            f"Running latexmk on {filename} did not produce a LaTeX "
+            f"{type} file as needed. I do not know how to build "
+            f"a {type} from this '.dtx' file."
+        )