fix logical inversion in the semantics of detect_cython()

borg/archive.py

@@ -14,7 +14,7 @@ from io import BytesIO
 from . import xattr
 from .helpers import parse_timestamp, Error, uid2user, user2uid, gid2group, group2gid, \
     Manifest, Statistics, decode_dict, st_mtime_ns, make_path_safe, StableDict, int_to_bigint, bigint_to_int, detect_cython
-if not detect_cython():
+if detect_cython():
     from .platform import acl_get, acl_set
     from .chunker import Chunker
     from .hashindex import ChunkIndex

borg/archiver.py

@@ -20,7 +20,7 @@ from .helpers import Error, location_validator, format_time, format_file_size, \
     get_cache_dir, get_keys_dir, format_timedelta, prune_within, prune_split, \
     Manifest, remove_surrogates, update_excludes, format_archive, check_extension_modules, Statistics, \
     is_cachedir, bigint_to_int, ChunkerParams, CompressionSpec, detect_cython
-if not detect_cython():
+if detect_cython():
     from .compress import Compressor, COMPR_BUFFER
     from .upgrader import AtticRepositoryUpgrader
     from .repository import Repository

borg/helpers.py

@@ -29,9 +29,9 @@ def detect_cython():
     which, when set (to anything) will disable includes of Cython
     libraries in key places to enable usage docs to be built.
     """
-    return os.environ.get('BORG_CYTHON_DISABLE')
+    return not os.environ.get('BORG_CYTHON_DISABLE')
 
-if not detect_cython():
+if detect_cython():
     from . import hashindex
     from . import chunker
     from . import crypto

borg/key.py

@@ -8,7 +8,7 @@ import hmac
 from hashlib import sha256
 
 from .helpers import IntegrityError, get_keys_dir, Error, detect_cython
-if not detect_cython():
+if detect_cython():
     from .crypto import pbkdf2_sha256, get_random_bytes, AES, bytes_to_long, long_to_bytes, bytes_to_int, num_aes_blocks
     from .compress import Compressor, COMPR_BUFFER
 

borg/repository.py

@@ -9,7 +9,7 @@ import sys
 from zlib import crc32
 
 from .helpers import Error, IntegrityError, read_msgpack, write_msgpack, unhexlify, detect_cython
-if not detect_cython():
+if detect_cython():
     from .hashindex import NSIndex
 from .locking import UpgradableLock
 from .lrucache import LRUCache