Bash hangs waiting for children (already dead)?

[Keegan, David]

Configuration Information [Automatically generated, do not change]:
Machine: sparc
OS: solaris2.7
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='sparc'
-DCONF_OSTYPE='solaris2.7' -DCONF_MACHTYPE='sparc-sun-solaris2.7'
-DCONF_VENDOR='sun' -DSHELL -DHAVE_CONFIG_H  -D_LARGEFILE_SOURCE
-D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE -I.  -I. -I./include -I./lib
-I/usr/local/include -g -O2
uname output: SunOS dlsparc9 5.7 Generic_106541-11 sun4u sparc
SUNW,Ultra-250
Machine Type: sparc-sun-solaris2.7

Bash Version: 2.04
Patch Level: 0
Release Status: release

Description:
   Bash is running a fairly deeply nested set of shell functions in a
   test set-up. When stdout and stderr of the top level shell function
   are to the terminal, all is well. When stderr and stdout of the top
   level function are piped into tee as follows

      $ TopLevelShellFunction 2>&1 | tee test.log

   bash hangs after up to an hour or so, but in a different location
   each time. Here is the process tree with what each instance of bash
   is doing according to truss. The last instance of bash is in a loop
   constantly repeating the call to waitid().

   28264 /usr/local/bin/bash -i # Interactive bash.
   waitid(P_ALL, 0, 0xFFBEB728, WEXITED|WTRAPPED|WSTOPPED) (sleeping...)

     12715 tee -a /part2/dkeegan/sof/1/../HaTestResults/10/hdlsparc9.log
     read(0, 0x00021190, 5120)  (sleeping...)


       12712 /usr/local/bin/bash -i # Bash running HadrTest piped into tee.
       read(4, 0xFFBE3F78, 128) (sleeping...)

         26440 /usr/local/bin/bash -i
         read(4, 0xFFBE3F78, 128)       (sleeping...)

           26514 /usr/local/bin/bash -i In a tight loop.
           waitid(P_ALL, 0, 0xFFBE3BF8, WEXITED|WTRAPPED)       Err#10
ECHILD

Repeat-By:
   I can't give any code that causes the problem as it happens at a
   different stage in the test process each time.


Any suggestions as to what might be causing this gratefully received.

Regards,
David Keegan.