[GR-68273] Fix two emulated posix shortcomings reported on Github.

graalpython/com.oracle.graal.python.test/src/tests/test_posix.py

@@ -173,6 +173,31 @@ def test_pipe(self):
             os.close(fd1)
             os.close(fd2)
 
+    @unittest.skipIf(sys.platform != 'linux', 'mkfifo is a linux command')
+    def test_seek_pipe(self):
+        new_file_path = './myscript.sh'
+        with io.open(new_file_path, 'w') as script:
+            script.write("""#!/bin/sh
+            mkfifo testpipe
+            echo "4" > testpipe &
+            """)
+        try:
+            st = os.stat(new_file_path)
+            os.chmod(new_file_path, st.st_mode | stat.S_IEXEC)
+            os.system(new_file_path)
+            with io.open("testpipe", "rb") as r:
+                out = r.read(1)
+            assert out == b"4", out
+        finally:
+            try:
+                os.remove(new_file_path)
+            except:
+                pass
+            try:
+                os.remove("testpipe")
+            except:
+                pass
+
     def test_mkdir_rmdir(self):
         os.mkdir(TEST_FULL_PATH1)
         try:

graalpython/com.oracle.graal.python.test/src/tests/test_subprocess.py

@@ -162,6 +162,21 @@ def test_java_asserts(self):
                 result = subprocess.run([sys.executable, "-c", "import __graalpython__; not __graalpython__.java_assert()"])
             assert result.returncode == 0
 
+    def test_subprocess_inherits_environ(self):
+        import os
+        import subprocess
+        prev = os.environ.get("FOOBAR")
+        try:
+            expected_value = f"42{prev}".strip()
+            os.environ["FOOBAR"] = expected_value
+            out = subprocess.check_output([sys.executable, '-c', "import os; print(os.environ['FOOBAR'])"]).decode().strip()
+            assert out == expected_value, f"{out!r} != {expected_value!r}"
+        finally:
+            if prev:
+                os.environ["FOOBAR"] = prev
+            else:
+                del os.environ["FOOBAR"]
+
     @unittest.skipUnless(sys.implementation.name == 'graalpy', "GraalPy-specific test")
     @unittest.skipIf(sys.platform == 'win32', "TODO the cmd replacement breaks the test")
     def test_graal_python_args(self):

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/exception/OSErrorEnum.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -312,7 +312,7 @@ public static ErrorAndMessagePair fromException(Exception e, TruffleString.Equal
                     return new ErrorAndMessagePair(oserror, oserror.getMessage());
                 }
             } else { // Generic IOException
-                OSErrorEnum oserror = tryFindErrnoFromMessage(e);
+                OSErrorEnum oserror = tryFindErrnoFromMessage(e, eqNode);
                 if (oserror == null) {
                     return new ErrorAndMessagePair(OSErrorEnum.EIO, getMessage(e));
                 } else {
@@ -360,15 +360,13 @@ private static TruffleString getReason(FileSystemException e) {
     }
 
     @TruffleBoundary
-    private static OSErrorEnum tryFindErrnoFromMessage(Exception e) {
-        if (e.getMessage().contains("Broken pipe")) {
-            return OSErrorEnum.EPIPE;
-        }
-        Matcher m = ERRNO_PATTERN.matcher(e.getMessage());
+    private static OSErrorEnum tryFindErrnoFromMessage(Exception e, TruffleString.EqualNode eqNode) {
+        String message = e.getMessage();
+        Matcher m = ERRNO_PATTERN.matcher(message);
         if (m.find()) {
             return fromNumber(Integer.parseInt(m.group(1)));
         }
-        return null;
+        return OSErrorEnum.fromMessage(toTruffleStringUncached(message), eqNode);
     }
 
     @ValueType

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/EmulatedPosixSupport.java

@@ -527,10 +527,15 @@ public Buffer read(int fd, long length,
     }
 
     @TruffleBoundary
-    private static Buffer readBytesFromChannel(ReadableByteChannel channel, long size) throws IOException {
+    private static Buffer readBytesFromChannel(ReadableByteChannel channel, long sizeIn) throws IOException {
+        long size = sizeIn;
         if (channel instanceof SeekableByteChannel seekableByteChannel) {
-            long availableSize = seekableByteChannel.size() - seekableByteChannel.position();
-            size = Math.min(size, availableSize);
+            try {
+                long availableSize = seekableByteChannel.size() - seekableByteChannel.position();
+                size = Math.min(size, availableSize);
+            } catch (IOException e) {
+                // pass and read what we can
+            }
         }
         size = Math.min(size, MAX_READ);
         ByteBuffer dst = ByteBuffer.allocate((int) size);
@@ -2304,6 +2309,8 @@ public int forkExec(Object[] executables, Object[] args, Object cwd, Object[] en
                     throw createUnsupportedFeature("Only key=value environment variables are supported in fork_exec");
                 }
             }
+        } else {
+            envMap = new HashMap<>(environ);
         }
 
         String[] argStrings;