various cleanups, better parallelism and build-dir structure

python/install_python_bindings.py

@@ -9,11 +9,16 @@ import subprocess
 import sys
 
 if __name__ == "__main__":
-    os.environ["DCC_RS_TARGET"] = target = "release"
+    target = os.environ.get("DCC_RS_TARGET")
+    if target is None:
+        os.environ["DCC_RS_TARGET"] = target = "release"
     if "DCC_RS_DEV" not in os.environ:
         dn = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
         os.environ["DCC_RS_DEV"] = dn
 
+    # build the core library  in release + debug mode because
+    # as of Nov 2019 rPGP generates RSA keys which take
+    # prohibitively long for non-release installs
     os.environ["RUSTFLAGS"] = "-g"
     subprocess.check_call([
         "cargo", "build", "-p", "deltachat_ffi", "--" + target

python/src/deltachat/_build.py

@@ -29,7 +29,10 @@ def ffibuilder():
             extra_link_args = []
         else:
             raise NotImplementedError("Compilation not supported yet on Windows, can you help?")
-        objs = [os.path.join(projdir, 'target', target, 'libdeltachat.a')]
+        target_dir = os.environ.get("CARGO_TARGET_DIR")
+        if target_dir is None:
+            target_dir = os.path.join(projdir, 'target')
+        objs = [os.path.join(target_dir, target, 'libdeltachat.a')]
         assert os.path.exists(objs[0]), objs
         incs = [os.path.join(projdir, 'deltachat-ffi')]
     else:

python/tox.ini

@@ -1,19 +1,22 @@
 [tox]
 # make sure to update environment list in travis.yml and appveyor.yml
 envlist =
-    py35
+    py37
     lint
     auditwheels
 
 [testenv]
 commands = 
-    pytest -n6 -v -rsXx {posargs:tests}
-    python tests/package_wheels.py {toxworkdir}/wheelhouse
+    pytest -n6 -v -rsXx -k "not qr" {posargs:tests} 
+    pytest -n6 -v -rsXx -k "qr" {posargs:tests} 
+    # python tests/package_wheels.py {toxworkdir}/wheelhouse
 passenv = 
     TRAVIS 
     DCC_RS_DEV
     DCC_RS_TARGET
     DCC_PY_LIVECONFIG
+    CARGO_TARGET_DIR
+    RUSTC_WRAPPER
 deps = 
     pytest
     pytest-rerunfailures