diff --git a/tox.ini b/tox.ini
index 392cad2cb1..712f1ecbbe 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,13 +12,10 @@ skip_missing_interpreters = true
 
 [testenv]
 description = run the tests with pytest under {basepython}
-setenv = VIRTUALENV_DOWNLOAD = 0
-         PIP_DISABLE_VERSION_CHECK = 1
+setenv = PIP_DISABLE_VERSION_CHECK = 1
          COVERAGE_FILE = {toxworkdir}/.coverage.{envname}
 passenv = http_proxy https_proxy no_proxy SSL_CERT_FILE TOXENV CI TRAVIS TRAVIS_* APPVEYOR APPVEYOR_* CODECOV_*
-deps = setuptools >= 29.0.0
-       setuptools_scm >= 2.0.0, < 3
-       wheel >= 0.31.0
+deps = 
 extras = testing
 changedir = {toxinidir}/tests
 commands = pytest {posargs:--cov="{envsitepackagesdir}/tox" --cov-config="{toxinidir}/tox.ini"  --timeout=180 .}
@@ -33,7 +30,7 @@ commands = sphinx-build -d "{toxworkdir}/docs_doctree" doc "{toxworkdir}/docs_ou
 
 
 [testenv:fix-lint]
-description = run static analysis and style check using flake8
+description = format the code base to adhere to our styles, and complain about what we cannot do automatically
 basepython = python3.6
 passenv = {[testenv]passenv}
           HOMEPATH
@@ -41,6 +38,7 @@ passenv = {[testenv]passenv}
           # `error setting certificate verify locations` error
           PROGRAMDATA
 extras = lint
+skip_install = True
 changedir = {toxinidir}
 commands = pre-commit run --all-files --show-diff-on-failure
            python -c 'print("hint: run {envdir}/bin/pre-commit install to add checks as pre-commit hook")'
@@ -53,6 +51,8 @@ deps = {[testenv]deps}
        coverage >= 4.4.1, < 5
        diff_cover
 skip_install = True
+passenv = {[testenv]passenv}
+          DIFF_AGAINST
 setenv = COVERAGE_FILE={toxworkdir}/.coverage
 changedir = {toxinidir}
 commands = coverage erase
@@ -106,7 +106,7 @@ max-line-length = 99
 ignore = E203, W503
 
 [coverage:run]
-branch = false
+branch = true
 
 [coverage:report]
 skip_covered = True