fix custom workdir support regression

Author: xvik

src/main/groovy/ru/vyarus/gradle/plugin/python/cmd/Python.groovy

@@ -305,7 +305,7 @@ class Python {
         // on win non global python could be called only through cmd
         String exec = withCmd ? 'cmd'
                 // use absolute python path if work dir set (relative will simply not work)
-                : (wrkDirUsed && customBinaryPath ? CliUtils.canonicalPath(executable) : executable)
+                : (wrkDirUsed && customBinaryPath ? project.file(executable).canonicalPath : executable)
         String[] cmd = withCmd ?
                 CliUtils.wincmdArgs(executable, project.projectDir, prepareArgs(args), wrkDirUsed)
                 : prepareArgs(args)

src/main/groovy/ru/vyarus/gradle/plugin/python/util/CliUtils.groovy

@@ -204,6 +204,8 @@ final class CliUtils {
     /**
      * Format canonical path WITHOUT following symlinks (which {@link File#getCanonicalPath()} do). Used to
      * remove redundant ".." parts in path.
+     * <p>
+     * Relative path will remain relative!
      *
      * @param file file or directory path
      * @return canonical path

src/test/groovy/ru/vyarus/gradle/plugin/python/multimodule/PythonUsedInSubmoduleKitTest.groovy

@@ -176,4 +176,39 @@ class PythonUsedInSubmoduleKitTest extends AbstractKitTest {
         !result.output.contains("${projectName()}${File.separator}.gradle${File.separator}python")
         result.output.contains("${projectName()}${File.separator}sub${File.separator}python")
     }
+
+    def "Check submodule python call with custom work dir"() {
+
+        setup:
+        file('settings.gradle') << ' include "sub"'
+        file('sub').mkdir()
+        build """                        
+            plugins {
+                id 'ru.vyarus.use-python' apply false
+            }
+            
+            allprojects {
+               apply plugin: 'ru.vyarus.use-python' 
+            }                        
+            
+            subprojects {  
+                python {
+                    pip 'click:6.7'
+                }
+                                                                                     
+                task sample(type: PythonTask) {
+                    command = '-c print(\\'samplee\\')'
+                    workDir = 'src'
+                }
+            }
+        """
+
+        when: "run sub task"
+        debug()
+        BuildResult result = run(':sub:sample')
+
+        then: "task successful"
+        result.task(':sub:sample').outcome == TaskOutcome.SUCCESS
+        result.output.contains('samplee')
+    }
 }