Error(s) in re-building vignettes:
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--- re-building ‘GiRaF_introduction.Rnw’ using knitr
Error: processing vignette 'GiRaF_introduction.Rnw' failed with diagnostics:
Running 'texi2dvi' on 'GiRaF_introduction.tex' failed.
LaTeX errors:
! LaTeX Error: Command \G already defined.
               Or name \end... illegal, see p.192 of the manual.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

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Type  H <return>  for immediate help.
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! LaTeX Error: Command \G unavailable in encoding T1.

See the LaTeX manual or
--- failed re-building ‘GiRaF_introduction.Rnw’

SUMMARY: processing the following file failed:
  ‘GiRaF_introduction.Rnw’

Error: Vignette re-building failed.
Execution halted