add wd via LSOF function that returns error

src/cpp/core/include/core/system/PosixSystem.hpp

@@ -262,6 +262,7 @@ FilePath currentWorkingDirMac(PidType pid);
 #ifndef __APPLE__
 // Determine current working directory of a given process by shelling out
 // to lsof; used on systems without procfs.
+core::Error currentWorkingDirViaLsof(PidType pid, FilePath* pPath);
 FilePath currentWorkingDirViaLsof(PidType pid);
 
 // Determine current working directory of a given process via procfs; returns

src/cpp/core/system/PosixSystem.cpp

@@ -1295,8 +1295,10 @@ FilePath currentWorkingDirMac(PidType pid)
 #ifndef __APPLE__
 
 // NOTE: disabled on macOS; prefer using 'currentWorkingDirMac()'
-FilePath currentWorkingDirViaLsof(PidType pid)
+Error currentWorkingDirViaLsof(PidType pid, FilePath *pPath)
 {
+ *pPath = FilePath();
+
  // lsof -a -p PID -d cwd -Fn
  //
  shell_utils::ShellCommand cmd("lsof");
@@ -1310,12 +1312,13 @@ FilePath currentWorkingDirViaLsof(PidType pid)
  core::system::ProcessResult result;
  Error error = runCommand(cmd, options, &result);
  if (error)
- {
- LOG_ERROR(error);
- return FilePath();
- }
+ return error;
+
  if (result.exitStatus != 0)
- return FilePath();
+ return unknownError(
+ "Failed to run lsof - exited with code " + std::to_string(result.exitStatus) + 
+ (result.stdErr.empty() ? "" : " (" + result.stdErr + ")"),
+ ERROR_LOCATION);
 
  // lsof outputs multiple lines, which varies by platform. We want the one
  // starting with lowercase 'n', after that is the current working directory.
@@ -1327,17 +1330,36 @@ FilePath currentWorkingDirViaLsof(PidType pid)
  pos++;
  size_t finalPos = result.stdOut.find_first_of('\n', pos);
  if (finalPos != std::string::npos)
- return FilePath(result.stdOut.substr(pos, finalPos - pos));
+ {
+ *pPath = FilePath(result.stdOut.substr(pos, finalPos - pos));
+ return Success();
+ }
  else
- return FilePath(result.stdOut.substr(pos));
+ {
+ *pPath = FilePath(result.stdOut.substr(pos));
+ return Success();
+ }
  }
 
  // next line
  pos = result.stdOut.find_first_of('\n', pos);
  pos++;
  }
 
- return FilePath();
+ return Success();
+}
+
+
+// NOTE: disabled on macOS; prefer using 'currentWorkingDirMac()'
+FilePath currentWorkingDirViaLsof(PidType pid)
+{
+ FilePath path;
+ Error error = currentWorkingDirViaLsof(pid, &path);
+
+ if (error)
+ LOG_ERROR(error);
+
+ return path;
 }
 
 FilePath currentWorkingDirViaProcFs(PidType pid)