Distribution of GPL'd works has requirements; copyleft will not function

without placing requirements on redistribution.  However, some requirements

are more likely to cause compliance difficult than others.  This

chapter\footnote{Note that this chapter refers heavily to specific provisions

  and language in

  \hyperref[GPLv2s3-full-text]{GPLv2\S3}

  and \hyperref[GPLv3s6-full-text]{GPLv3\S6}.

  It may be helpful  to review \S~\ref{GPLv2s3} and \S~\ref{GPLv3s6} first,

  and then have a copy of each license open while reading this

  section.}  explains some the specific requirements placed upon

distributors of GPL'd software that redistributors are most likely to

overlook, yielding compliance problems.

First, \hyperref[GPLv2s1]{GPLv2\S1} and \hyperref[GPLv2s4]{GPLv2\S4} require

that the full license text must accompany every distribution (either in

source or binary form) of each licensed work.  Strangely, this requirement is

responsible for a surprisingly significant fraction of compliance errors; too

often, physical products lack required information about the presence of

GPL’d programs and the applicable license terms.  Automated build processes

can and should carry a copy of the license from the the source distribution

into the final binary firmware package for embedded products.  Such

automation usually achieves compliance regarding license inclusion

requirements\footnote{At least one COGEO recommends the

  \href{https://www.yoctoproject.org/}{Yocto Project}, since its engineers

  have designed such features into it build process.}

\label{GPLv2s3-full-text}

\label{GPLv3s6-full-text}