Rewrite of "--remote", to use a temporary file for information exchange instead of a SysV IPC message queue, to correct the fault where "make check -j32" would fail due to every PV exit removing the message queue.

docs/NEWS.md

@@ -1,5 +1,6 @@
 ### 1.8.x-UNRELEASED
 
+ * fix: replaced "`--remote`" mechanism, using a temporary file instead of SysV IPC, so it can work reliably even when there are multiple PV instances
  * fix: corrected compilation failure when without IPC support
  * cleanup: compilation warnings fixed on non-IPC and MacOS systems
 

docs/pv.1

@@ -689,13 +689,11 @@ before using
 .IP \(bu 3
 The
 .B -R
-option is not available on Cygwin without
-.B cygserver
-running (SYSV IPC is needed). To fix this, start
-.B cygserver
-before running the instance of
-.B pv
-you want, at runtime, to change the parameters of.
+option requires that either
+.B /run/user/<uid>/
+or
+.B /tmp/
+can be written to, for inter-process communication.
 .P
 If you find any other problems, please report them.
 

docs/pv.1.md

@@ -517,10 +517,8 @@ The following problems are known to exist in **pv**:
     is needed to handle the terminal scrolling). To fix this, start
     **cygserver** before using **pv -c**.
 
--   The **-R** option is not available on Cygwin without **cygserver**
-    running (SYSV IPC is needed). To fix this, start **cygserver**
-    before running the instance of **pv** you want, at runtime, to
-    change the parameters of.
+-   The **-R** option requires that either **/run/user/\<uid\>/** or
+    **/tmp/** can be written to, for inter-process communication.
 
 If you find any other problems, please report them.