NAME

       bear-intercept - intercept command executions in user space.

SYNOPSIS

       bear intercept [options] -- [build command]

DESCRIPTION

       The  command  executes the given build command and generates an output file which contains
       all process execution related events has happened during the build.

       The process execution events are: start, signal, termination.   The  output  will  contain
       only  the  child  processes.   Depending  on  the  interception mode the output might only
       contain a subset of the executed commands.  Interception modes are:

       • preload uses the LD_PRELOAD or DYLD_INSERT_LIBRARIES mechanisms provided by the  dynamic
         linker.   The  pre-loaded  library  hijacks  the process execution calls, and executes a
         supervisor process, which reports the execution.  The method fails when  the  executable
         statically linked, or security protection disables the dynamic linker.

       • wrapper  mode  interpose  a  wrapper  program to the build.  The wrapper sends execution
         report and calls the original program.  The method fails when the build  system  is  not
         flexible enough for interposing build tools.

       The  reports  are  collected  by  the intercept over a gRPC interface, and written into an
       output file.

OPTIONS

       --version
              Print version number.

       --help Print help message.

       --verbose
              Enable verbose logging.

       --output file
              Specify output file.  (Default file  name  provided.)   The  output  is  a  command
              execution  list, with some extra information.  The syntax is detailed in a separate
              section.

       --force-preload
              Force to use the preload method to intercept the children processes.

       --force-wrapper
              Force to use the wrapper method to intercept the children processes.

EXIT STATUS

       The exit status of the program is the exit status of the build command.  Except  when  the
       program itself crashes, then it sets to non zero.

OUTPUT FILE

       The output file has JSON lines (https://jsonlines.org/) format, where each line terminated
       with \n line separator and each line is a JSON object.

       The JSON objects are process execution events: process start, process got signal,  process
       terminated.   (For the schema of these events, please consult with the source code of this
       project.)

TROUBLESHOOTING

       The potential problems you can face with are: the build with and without the  interception
       behaves differently (eg.: the build crash with the intercept tool, but succeed otherwise).
       The output is empty, and it failed to intercept the  children  process  execution  by  the
       build command.

       The  most  common  cause  for  empty outputs is that the build command did not execute any
       commands.  The reason for that could  be,  because  incremental  builds  not  running  the
       compilers  if everything is up-to-date.  Remember, intercept does not understand the build
       file (eg.: makefile), but intercepts the executed commands.

       There could be many reasons for any of these failures.  It’s better to  consult  with  the
       project wiki page for known problems, before open a bug report.

SEE ALSO

       bear(1)

COPYRIGHT

       Copyright (C) 2012-2022 by László Nagy <https://github.com/rizsotto/Bear>

AUTHORS

       László Nagy.