This is WhatsHap 2.8 running under Python 3.9.23
[W::hts_idx_load3] The index file is older than the data file: FFPE_HD789_01_p2_gDNA_01_A23MHWWLT4_1.recalibrated.bam.bai
[W::hts_idx_load3] The index file is older than the data file: FFPE_HD789_01_p2_gDNA_01_A23MHWWLT4_1.recalibrated.bam.bai
[E::idx_find_and_load] Could not retrieve index file for 'input_filtered.vcf.gz'
[E::idx_find_and_load] Could not retrieve index file for 'input_filtered.vcf.gz'
[E::idx_find_and_load] Could not retrieve index file for 'input_filtered.vcf.gz'
Working on 2 samples from 2 families
WARNING: Skipping duplicated position 1257406 on chromosome 'chr1' Hiding further warnings of this type, use --debug to show

# Working on contig chr1 in individual FFPE_HD789_01_p2_gDNA_01_A23MHWWLT4_1
Found 10934 usable heterozygous variants (0 skipped due to missing genotypes)
[W::hts_idx_load3] The index file is older than the data file: FFPE_HD789_01_p2_gDNA_01_A23MHWWLT4_1.recalibrated.bam.bai
Number of supplementary alignments: 0
Number of non-singleton groups: 1230070
Skipped 0 groups
Found 4801231 reads covering 10934 variants
Kept 1371608 reads that cover at least two variants each
Selected 36401 most phase-informative reads covering 7325 variants
Best-case phasing would result in 2266 non-singleton phased blocks (0 singletons). 
Phasing 1 sample by solving the MEC problem ...
Largest block contains 256 variants (3.5% of accessible variants) between position 152213249 and 152221071

# Working on contig chr1 in individual reference-NA12878
Found 211 usable heterozygous variants (0 skipped due to missing genotypes)
WARNING: Sample 'reference-NA12878' not found in any BAM/CRAM file.
Found 0 reads covering 0 variants
Kept 0 reads that cover at least two variants each
Selected 0 most phase-informative reads covering 0 variants
Best-case phasing would result in 0 non-singleton phased blocks (0 singletons). 
Phasing 1 sample by solving the MEC problem ...
No. of phased blocks: 0
WARNING: Ignoring existing phasing information found in input VCF (PS tag exists).

# Resource usage
Maximum memory usage: 7.409 GB
Time spent reading BAM/CRAM:                  962.5 s
Time spent parsing VCF:                         0.3 s
Time spent selecting reads:                   119.6 s
Time spent phasing:                            29.6 s
Time spent writing VCF:                         0.5 s
Time spent finding components:                  0.1 s
Time spent on rest:                             9.5 s
Total elapsed time:                          1122.2 s