I downloaded the latest nightly build of the `.deb` package and installed in a fresh Linux machine. When trying to list all available filters I get an JS stacktrace error.

```
gpac -h filters
Listing 127 supported filters:
inspect: Inspect packets
probe: Probe source
compositor: Compositor
mp4dmx: ISOBMFF/QT demultiplexer
bifsdec: MPEG-4 BIFS decoder
odfdec: MPEG-4 OD decoder
fin: File input
btplay: BT/XMT/X3D loader
httpin: HTTP input
svgplay: SVG loader
rfimg: JPG/J2K/PNG/BMP reframer
imgdec: PNG/JPG decoder
rfadts: ADTS reframer
rflatm: LATM reframer
rfmp3: MP3 reframer
faad: FAAD decoder
maddec: MAD decoder
j2kdec: OpenJPEG2000 decoder
rfac3: AC3 reframer
a52dec: A52 decoder
rfamr: AMR/EVRC reframer
oggdmx: OGG demultiplexer
vorbisdec: Vorbis decoder
theoradec: Theora decoder
m2tsdmx: MPEG-2 TS demultiplexer
sockin: UDP/TCP input
osvcdec: OpenSVC decoder
lsrdec: MPEG-4 LASeR decoder
safdmx: SAF demultiplexer
dashin: MPEG-DASH and HLS client
cdcrypt: CENC decryptor
cecrypt: CENC encryptor
mp4mx: ISOBMFF/QT multiplexer
rfqcp: QCP reframer
rfh263: H263 reframer
rfmpgvid: M1V/M2V/M4V reframer
nhntr: NHNT reader
nhmlr: NHML reader
rfnalu: AVC/HEVC reframer
m2psdmx: MPEG PS demultiplexer
avidmx: AVI demultiplexer
txtin: Subtitle loader
ttxtdec: TTXT/TX3G decoder
vttdec: WebVTT decoder
ttmldec: TTML decoder
rtpin: RTP/RTSP/SDP input
fout: File output
uflatm: Raw AAC to LATM writer
ufadts: ADTS writer
ufmhas: MHAS writer
reframer: Media Reframer
writegen: Stream to file
ufnalu: AVC/HEVC to AnnexB writer
writeqcp: QCP writer
ufvtt: WebVTT unframer
nhntw: NHNT writer
nhmlw: NHML writer
vobsubdmx: VobSub parser
avimx: AVI multiplexer
aout: Audio output
ufm4v: M4V writer
ufvc1: VC1 writer
resample: Audio resampler
vout: Video output
vcrop: Video crop
vflip: Video flip
rfrawvid: RAW video reframer
rfpcm: PCM reframer
jpgenc: JPG encoder
pngenc: PNG encoder
rewind: Audio/Video rewinder
flist: Sources concatenator
m2tsmx: MPEG-2 TS multiplexer
dasher: DASH and HLS segmenter
tileagg: HEVC tile aggregator
tilesplit: HEVC tile bitstream splitter
pin: pipe input
pout: pipe output
gsfmx: GSF Multiplexer
gsfdmx: GSF demultiplexer
sockout: UDP/TCP output
rfav1: AV1/IVF/VP9 reframer
ufobu: IVF/OBU/annexB writer
routein: ROUTE input
rtpout: RTP Streamer
rtspout: RTSP Server
httpout: HTTP Server
hevcsplit: HEVC tile splitter
hevcmerge: HEVC Tile merger
rfflac: FLAC reframer
rfmhas: MPEH-H Audio Stream reframer
rfprores: ProRes reframer
tssplit: MPEG Transport Stream splitter
bsrw: Compressed bitstream rewriter
bssplit: Compressed layered bitstream splitter
bsagg: Compressed layered bitstream aggregator
ufttxt: TX3G unframer
tx3g2srt: TX3G to SRT
tx3g2vtt: TX3G to WebVTT
tx3g2ttml: TX3G to TTML
vtt2tx3g: WebVTT to TX3G
rfsrt: SRT reframer
ttml2vtt: TTML to WebVTT
ttml2srt: TTML to SRT
mpeghdec: MPEG-H Audio decoder
ffdmx: FFMPEG demultiplexer
ffdmxpid: FFMPEG demultiplexer
ffdec: FFMPEG decoder
ffavin: FFMPEG AV Capture
ffsws: FFMPEG video rescaler
ffenc: FFMPEG encoder
ffmx: FFMPEG multiplexer
ffavf: FFMPEG AVFilter
jsf: JavaScript filter
routeout: ROUTE output
rftruehd: TrueHD reframer
cryptin: CryptFile input
cryptout: CryptFile output
restamp: Packet timestamp rewriter
oggmx: OGG multiplexer
unframer: Stream unframer
writeuf: Stream to unframed format
uncvdec: UNCV decoder
ghidmx: GHI demultiplexer
evgs: EVG video rescaler
ccdec: Closed-Caption decoder
ohevcdec: OpenHEVC decoder
glpush: GPU texture uploader
uncvg: Uncompressed Video File Format Generator Utility
avmix: Audio Video Mixer
thumbs: Thumbnail collection generator
[FreeType] Default fonts not valid, rescanning font directories /usr/share/fonts/
[avgen] Error initializing filter
[avgen] Error: Fonts not found (first was SANS) and no default font available!
Check your GPAC configuration, or use `-rescan-fonts` to refresh font directory.

    at put_image (/usr/share/gpac/scripts/jsf/avgen/init.js:358)
    at <anonymous> (/usr/share/gpac/scripts/jsf/avgen/init.js:247)

Filter avgen failed to setup: Bad Parameter
```

Version: `2.5-DEV-rev17-g8d7cac0b-master`
Fresh Ubuntu/Linux install nightly fails
This is a GitHub Issue
repo:gpac
owner:gpac
Title : Fresh Ubuntu/Linux install nightly fails
Issue date:

--- start body ---
I downloaded the latest nightly build of the `.deb` package and installed in a fresh Linux machine. When trying to list all available filters I get an JS stacktrace error.

```
gpac -h filters
Listing 127 supported filters:
inspect: Inspect packets
probe: Probe source
compositor: Compositor
mp4dmx: ISOBMFF/QT demultiplexer
bifsdec: MPEG-4 BIFS decoder
odfdec: MPEG-4 OD decoder
fin: File input
btplay: BT/XMT/X3D loader
httpin: HTTP input
svgplay: SVG loader
rfimg: JPG/J2K/PNG/BMP reframer
imgdec: PNG/JPG decoder
rfadts: ADTS reframer
rflatm: LATM reframer
rfmp3: MP3 reframer
faad: FAAD decoder
maddec: MAD decoder
j2kdec: OpenJPEG2000 decoder
rfac3: AC3 reframer
a52dec: A52 decoder
rfamr: AMR/EVRC reframer
oggdmx: OGG demultiplexer
vorbisdec: Vorbis decoder
theoradec: Theora decoder
m2tsdmx: MPEG-2 TS demultiplexer
sockin: UDP/TCP input
osvcdec: OpenSVC decoder
lsrdec: MPEG-4 LASeR decoder
safdmx: SAF demultiplexer
dashin: MPEG-DASH and HLS client
cdcrypt: CENC decryptor
cecrypt: CENC encryptor
mp4mx: ISOBMFF/QT multiplexer
rfqcp: QCP reframer
rfh263: H263 reframer
rfmpgvid: M1V/M2V/M4V reframer
nhntr: NHNT reader
nhmlr: NHML reader
rfnalu: AVC/HEVC reframer
m2psdmx: MPEG PS demultiplexer
avidmx: AVI demultiplexer
txtin: Subtitle loader
ttxtdec: TTXT/TX3G decoder
vttdec: WebVTT decoder
ttmldec: TTML decoder
rtpin: RTP/RTSP/SDP input
fout: File output
uflatm: Raw AAC to LATM writer
ufadts: ADTS writer
ufmhas: MHAS writer
reframer: Media Reframer
writegen: Stream to file
ufnalu: AVC/HEVC to AnnexB writer
writeqcp: QCP writer
ufvtt: WebVTT unframer
nhntw: NHNT writer
nhmlw: NHML writer
vobsubdmx: VobSub parser
avimx: AVI multiplexer
aout: Audio output
ufm4v: M4V writer
ufvc1: VC1 writer
resample: Audio resampler
vout: Video output
vcrop: Video crop
vflip: Video flip
rfrawvid: RAW video reframer
rfpcm: PCM reframer
jpgenc: JPG encoder
pngenc: PNG encoder
rewind: Audio/Video rewinder
flist: Sources concatenator
m2tsmx: MPEG-2 TS multiplexer
dasher: DASH and HLS segmenter
tileagg: HEVC tile aggregator
tilesplit: HEVC tile bitstream splitter
pin: pipe input
pout: pipe output
gsfmx: GSF Multiplexer
gsfdmx: GSF demultiplexer
sockout: UDP/TCP output
rfav1: AV1/IVF/VP9 reframer
ufobu: IVF/OBU/annexB writer
routein: ROUTE input
rtpout: RTP Streamer
rtspout: RTSP Server
httpout: HTTP Server
hevcsplit: HEVC tile splitter
hevcmerge: HEVC Tile merger
rfflac: FLAC reframer
rfmhas: MPEH-H Audio Stream reframer
rfprores: ProRes reframer
tssplit: MPEG Transport Stream splitter
bsrw: Compressed bitstream rewriter
bssplit: Compressed layered bitstream splitter
bsagg: Compressed layered bitstream aggregator
ufttxt: TX3G unframer
tx3g2srt: TX3G to SRT
tx3g2vtt: TX3G to WebVTT
tx3g2ttml: TX3G to TTML
vtt2tx3g: WebVTT to TX3G
rfsrt: SRT reframer
ttml2vtt: TTML to WebVTT
ttml2srt: TTML to SRT
mpeghdec: MPEG-H Audio decoder
ffdmx: FFMPEG demultiplexer
ffdmxpid: FFMPEG demultiplexer
ffdec: FFMPEG decoder
ffavin: FFMPEG AV Capture
ffsws: FFMPEG video rescaler
ffenc: FFMPEG encoder
ffmx: FFMPEG multiplexer
ffavf: FFMPEG AVFilter
jsf: JavaScript filter
routeout: ROUTE output
rftruehd: TrueHD reframer
cryptin: CryptFile input
cryptout: CryptFile output
restamp: Packet timestamp rewriter
oggmx: OGG multiplexer
unframer: Stream unframer
writeuf: Stream to unframed format
uncvdec: UNCV decoder
ghidmx: GHI demultiplexer
evgs: EVG video rescaler
ccdec: Closed-Caption decoder
ohevcdec: OpenHEVC decoder
glpush: GPU texture uploader
uncvg: Uncompressed Video File Format Generator Utility
avmix: Audio Video Mixer
thumbs: Thumbnail collection generator
[FreeType] Default fonts not valid, rescanning font directories /usr/share/fonts/
[avgen] Error initializing filter
[avgen] Error: Fonts not found (first was SANS) and no default font available!
Check your GPAC configuration, or use `-rescan-fonts` to refresh font directory.

    at put_image (/usr/share/gpac/scripts/jsf/avgen/init.js:358)
    at <anonymous> (/usr/share/gpac/scripts/jsf/avgen/init.js:247)

Filter avgen failed to setup: Bad Parameter
```

Version: `2.5-DEV-rev17-g8d7cac0b-master`
--- end body ---
