Dockerfiles: set LANG=C.UTF-8

Issue #184 to avoid issue with printing UTF-8 text to sidecar

Dockerfile

@@ -20,6 +20,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   tesseract-ocr-spa \
   tesseract-ocr-deu
 
+ENV LANG=C.UTF-8
+
 RUN python3 -m venv --system-site-packages /appenv
 
 # This installs the latest binary wheel instead of the code in the current

Dockerfile.tess4

@@ -30,6 +30,8 @@ RUN apt-get update \
 		tesseract-ocr-rus \
 		tesseract-ocr-chi-sim 
 
+ENV LANG=C.UTF-8
+
 RUN python3 -m venv --system-site-packages /appenv
 
 # This installs the latest binary wheel instead of the code in the current

tests/test_main.py

@@ -404,9 +404,13 @@ def test_force_ocr_on_pdf_with_no_images(spoof_tesseract_crash, resources,
 @pytest.mark.skipif(
     pytest.helpers.is_macos() and pytest.helpers.running_in_travis(),
     reason="takes too long to install language packs in Travis macOS homebrew")
-def test_french(spoof_tesseract_cache, resources, outpdf):
+def test_french(spoof_tesseract_cache, resources, outdir):
+    # Produce a sidecar too - implicit test that system locale is set up
+    # properly
+    sidecar = outdir / 'francais.txt'
     p, out, err = run_ocrmypdf(
-        resources / 'francais.pdf', outpdf, '-l', 'fra',
+        resources / 'francais.pdf', outdir / 'francais.pdf', '-l', 'fra',
+        '--sidecar', sidecar,
         env=spoof_tesseract_cache)
     print(os.environ)
     assert p.returncode == ExitCode.ok, \