Export COVERAGE_FILE and COVERAGE_PROCESS_START outside the command

On Windows you can't set env vars just before executing a command-line, so
move the definition of those variables to the CI environment

Author: nicoddemus

.travis.yml

@@ -82,7 +82,9 @@ jobs:
 before_script:
   - |
     if [[ "$PYTEST_NO_COVERAGE" != 1 ]]; then
-      export _PYTEST_TOX_COVERAGE_RUN="env COVERAGE_FILE=$PWD/.coverage COVERAGE_PROCESS_START=$PWD/.coveragerc coverage run --source {envsitepackagesdir}/_pytest/,$PWD/testing -m"
+      export COVERAGE_FILE=$PWD/.coverage
+      export COVERAGE_PROCESS_START=$PWD/.coveragerc
+      export _PYTEST_TOX_COVERAGE_RUN="coverage run --source {envsitepackagesdir}/_pytest/,$PWD/testing -m"
       export _PYTEST_TOX_EXTRA_DEP=coverage-enable-subprocess
     fi
 

scripts/prepare-coverage.bat

@@ -1,5 +1,7 @@
 if not defined PYTEST_NO_COVERAGE (
-    set "_PYTEST_TOX_COVERAGE_RUN=coverage run --source {envsitepackagesdir}/_pytest/,%CD%/testing -m"
+    set "COVERAGE_FILE=%CD%\.coverage"
+    set "COVERAGE_PROCESS_START=%CD%\.coveragerc"
+    set "_PYTEST_TOX_COVERAGE_RUN=coverage run --source {envsitepackagesdir}\_pytest\,%CD%\testing -m"
     set "_PYTEST_TOX_EXTRA_DEP=coverage-enable-subprocess"
     echo Coverage setup completed
 ) else (

tox.ini

@@ -19,7 +19,7 @@ envlist =
 [testenv]
 commands =
     {env:_PYTEST_TOX_COVERAGE_RUN:} pytest --lsof -ra {posargs:testing}
-passenv = USER USERNAME
+passenv = USER USERNAME COVERAGE_FILE COVERAGE_PROCESS_START
 setenv =
 deps =
     hypothesis>=3.56