Add CIBW_TEST_COMMAND and indent Makefile

Author: ddelange

.github/workflows/main.yml

@@ -48,7 +48,7 @@ jobs:
       - uses: actions/setup-python@v4
         with:
           python-version: '3.x'
-      - run: pip install cibuildwheel==2.15.0
+      - run: pip install cibuildwheel==2.16.2  # sync version with pypa/cibuildwheel below
       - id: set-matrix
         env:
           CIBW_PROJECT_REQUIRES_PYTHON: '==3.8.*'
@@ -82,13 +82,15 @@ jobs:
       if: runner.os == 'Linux'
       uses: docker/setup-qemu-action@v2
 
-    - uses: pypa/cibuildwheel@v2.15.0
+    - uses: pypa/cibuildwheel@v2.16.2  # sync version with pip install cibuildwheel above
       timeout-minutes: 10
       with:
         only: ${{ matrix.only }}
       env:
         CIBW_BUILD_VERBOSITY: 1
-        CIBW_BEFORE_BUILD: 'bash -c "make install_libmagic"'
+        MACOSX_DEPLOYMENT_TARGET: 11.0  # oldest available github runner ("macos-11" above)
+        CIBW_BEFORE_BUILD: bash -c "make install_libmagic"
+        CIBW_TEST_COMMAND: python -c "import magic; assert magic.Magic(mime=True).from_buffer(b'\x00\x00\x00\x1cftypisom\x00\x00\x02\x00isomiso2mp41\x00') == 'video/mp4'"
 
     - uses: actions/upload-artifact@v3
       with:

Makefile

@@ -3,14 +3,23 @@ SHELL := /bin/bash
 .PHONY: install_libmagic
 ## Install libmagic
 install_libmagic:
+	# Mac https://formulae.brew.sh/formula/libmagic
 	# Debian https://packages.ubuntu.com/libmagic1
+	# Alpine https://pkgs.alpinelinux.org/package/libmagic
 	# RHEL https://git.almalinux.org/rpms/file
-	# Mac https://formulae.brew.sh/formula/libmagic
 	# Windows https://github.com/julian-r/file-windows
-	( ( ( brew install libmagic || ( apt-get update && apt-get install -y libmagic1 ) ) || apk add --update libmagic ) || yum install file-libs ) || ( python -c 'import platform, sysconfig, io, zipfile, urllib.request; assert platform.system() == "Windows"; machine = "x86" if sysconfig.get_platform() == "win32" else "x64"; print(machine); zipfile.ZipFile(io.BytesIO(urllib.request.urlopen(f"https://github.com/julian-r/file-windows/releases/download/v5.44/file_5.44-build104-vs2022-{machine}.zip").read())).extractall(".")' && ls -ltra )
+	( ( ( \
+	    brew install libmagic \
+		|| ( apt-get update && apt-get install -y libmagic1 ) ) \
+		|| apk add --update libmagic ) \
+		|| yum install file-libs ) \
+		|| ( python -c 'import platform, sysconfig, io, zipfile, urllib.request; assert platform.system() == "Windows"; machine = "x86" if sysconfig.get_platform() == "win32" else "x64"; print(machine); zipfile.ZipFile(io.BytesIO(urllib.request.urlopen(f"https://github.com/julian-r/file-windows/releases/download/v5.44/file_5.44-build104-vs2022-{machine}.zip").read())).extractall(".")' && ls -ltra )
 	# on cibuildwheel, the lib needs to exist in the project before running setup.py
+	# copy lib into the magic dir, regardless of platform
 	python -c "import subprocess; from magic.loader import load_lib; lib = load_lib()._name; print(f'linking {lib}'); subprocess.check_call(['cp', lib, 'magic'])"
-	cp /usr/share/misc/magic.mgc magic || true # only on linux
+	# only on linux: additionally copy compiled db into magic dir
+	cp /usr/share/misc/magic.mgc magic || true
+	# check what was copied
 	ls -ltra magic
 
 .DEFAULT_GOAL := help

magic/loader.py

@@ -12,7 +12,7 @@ def _lib_candidates():
 
         paths = [
             here,
-            os.path.abspath("."),
+            os.path.abspath('.'),
             '/opt/local/lib',
             '/usr/local/lib',
             '/opt/homebrew/lib',
@@ -29,18 +29,23 @@ def _lib_candidates():
             # find_library searches in %PATH% but not the current directory,
             # so look for both
             yield os.path.join(here, '%s.dll' % i)
-            yield os.path.join(os.path.abspath("."), '%s.dll' % i)
+            yield os.path.join(os.path.abspath('.'), '%s.dll' % i)
             yield find_library(i)
 
     elif sys.platform == 'linux':
-        # on some linux systems (musl/alpine), find_library('magic') returns None
-        yield subprocess.check_output(
-            "( ldconfig -p | grep 'libmagic.so.1' | grep -o '/.*' ) || echo '/usr/lib/libmagic.so.1'",
-            shell=True,
-            universal_newlines=True,
-        ).strip()
-        yield os.path.join(here, 'libmagic.so.1')
-        yield os.path.join(os.path.abspath("."), 'libmagic.so.1')
+
+        prefixes = ['libmagic.so.1', 'libmagic.so']
+
+        for i in prefixes:
+            yield os.path.join(here, i)
+            yield os.path.join(os.path.abspath('.'), i)
+            # on some linux systems (musl/alpine), find_library('magic') returns None
+            # first try ldconfig with backup string in case of error
+            yield subprocess.check_output(
+                "( ldconfig -p | grep '{0}' | grep -o '/.*' ) || echo '/usr/lib/{0}'".format(i),
+                shell=True,
+                universal_newlines=True,
+            ).strip()
 
     yield find_library('magic')
 
@@ -53,9 +58,7 @@ def load_lib():
             continue
         try:
             return ctypes.CDLL(lib)
-        except OSError as exc:
+        except OSError:  # file not found
             pass
-    else:
-        # It is better to raise an ImportError since we are importing magic module
-        raise ImportError('failed to find libmagic. Check your installation')
+    raise ImportError('failed to find libmagic. Check your installation')